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Han Q, Hung YH, Zhang C, Bartels A, Rea M, Yang H, Park C, Zhang XQ, Fischer RL, Xiao W, Hsieh TF. Loss of linker histone H1 in the maternal genome influences DEMETER-mediated demethylation and affects the endosperm DNA methylation landscape. FRONTIERS IN PLANT SCIENCE 2022; 13:1070397. [PMID: 36618671 PMCID: PMC9813442 DOI: 10.3389/fpls.2022.1070397] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 12/01/2022] [Indexed: 06/17/2023]
Abstract
The Arabidopsis DEMETER (DME) DNA glycosylase demethylates the central cell genome prior to fertilization. This epigenetic reconfiguration of the female gamete companion cell establishes gene imprinting in the endosperm and is essential for seed viability. DME demethylates small and genic-flanking transposons as well as intergenic and heterochromatin sequences, but how DME is recruited to these loci remains unknown. H1.2 was identified as a DME-interacting protein in a yeast two-hybrid screen, and maternal genome H1 loss affects DNA methylation and expression of selected imprinted genes in the endosperm. Yet, the extent to which H1 influences DME demethylation and gene imprinting in the Arabidopsis endosperm has not been investigated. Here, we showed that without the maternal linker histones, DME-mediated demethylation is facilitated, particularly in the heterochromatin regions, indicating that H1-bound heterochromatins are barriers for DME demethylation. Loss of H1 in the maternal genome has a very limited effect on gene transcription or gene imprinting regulation in the endosperm; however, it variably influences euchromatin TE methylation and causes a slight hypermethylation and a reduced expression in selected imprinted genes. We conclude that loss of maternal H1 indirectly influences DME-mediated demethylation and endosperm DNA methylation landscape but does not appear to affect endosperm gene transcription and overall imprinting regulation.
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Affiliation(s)
- Qiang Han
- Department of Biology, Saint Louis University, St. Louis, MO, United States
| | - Yu-Hung Hung
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, United States
- Plants for Human Health Institute, North Carolina State University, Kannapolis, NC, United States
| | - Changqing Zhang
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, United States
- Plants for Human Health Institute, North Carolina State University, Kannapolis, NC, United States
| | - Arthur Bartels
- Department of Biology, Saint Louis University, St. Louis, MO, United States
| | - Matthew Rea
- Department of Biology, Saint Louis University, St. Louis, MO, United States
| | - Hanwen Yang
- Department of Biology, Saint Louis University, St. Louis, MO, United States
| | - Christine Park
- Department of Biology, Saint Louis University, St. Louis, MO, United States
| | - Xiang-Qian Zhang
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, United States
- Plants for Human Health Institute, North Carolina State University, Kannapolis, NC, United States
- College of Food Science and Engineering, Foshan University, Foshan, China
| | - Robert L. Fischer
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA, United States
| | - Wenyan Xiao
- Department of Biology, Saint Louis University, St. Louis, MO, United States
| | - Tzung-Fu Hsieh
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, United States
- Plants for Human Health Institute, North Carolina State University, Kannapolis, NC, United States
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Morgan BL, Donohue K. Parental methylation mediates how progeny respond to environments of parents and of progeny themselves. ANNALS OF BOTANY 2022; 130:883-899. [PMID: 36201313 PMCID: PMC9758305 DOI: 10.1093/aob/mcac125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 10/04/2022] [Indexed: 06/16/2023]
Abstract
BACKGROUND AND AIMS Environments experienced by both parents and offspring influence progeny traits, but the epigenetic mechanisms that regulate the balance of parental vs. progeny control of progeny phenotypes are not known. We tested whether DNA methylation in parents and/or progeny mediates responses to environmental cues experienced in both generations. METHODS Using Arabidopsis thaliana, we manipulated parental and progeny DNA methylation both chemically, via 5-azacytidine, and genetically, via mutants of methyltransferase genes, then measured progeny germination responses to simulated canopy shade in parental and progeny generations. KEY RESULTS We first found that germination of offspring responded to parental but not seed demethylation. We further found that parental demethylation reversed the parental effect of canopy in seeds with low (Cvi-1) to intermediate (Col) dormancy, but it obliterated the parental effect in seeds with high dormancy (Cvi-0). Demethylation did so by either suppressing germination of seeds matured under white-light (Cvi-1) or under canopy (Cvi-0), or by increasing the germination of seeds matured under canopy (Col). Disruption of parental methylation also prevented seeds from responding to their own light environment in one genotype (Cvi-0, most dormant), but it enabled seeds to respond to their own environment in another genotype (Cvi-1, least dormant). Using mutant genotypes, we found that both CG and non-CG DNA methylation were involved in parental effects on seed germination. CONCLUSIONS Parental methylation state influences seed germination more strongly than does the progeny's own methylation state, and it influences how seeds respond to environments of parents and progeny in a genotype-specific manner.
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Affiliation(s)
- Britany L Morgan
- University Program in Ecology Duke University, Durham, NC 27705, USA
- Center for Agricultural Synthetic Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Kathleen Donohue
- University Program in Ecology Duke University, Durham, NC 27705, USA
- Biology Department, Duke University, Durham, NC 27705, USA
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Zhou X, Wei M, Nie W, Xi Y, Peng L, Zheng Q, Tang K, Satheesh V, Wang Y, Luo J, Du X, Liu R, Yang Z, La H, Zhong Y, Yang Y, Zhu JK, Du J, Lei M. The H3K9me2-binding protein AGDP3 limits DNA methylation and transcriptional gene silencing in Arabidopsis. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2022; 64:2385-2395. [PMID: 36149781 DOI: 10.1111/jipb.13369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 09/20/2022] [Indexed: 06/16/2023]
Abstract
DNA methylation, a conserved epigenetic mark, is critical for tuning temporal and spatial gene expression. The Arabidopsis thaliana DNA glycosylase/lyase REPRESSOR OF SILENCING 1 (ROS1) initiates active DNA demethylation and is required to prevent DNA hypermethylation at thousands of genomic loci. However, how ROS1 is recruited to specific loci is not well understood. Here, we report the discovery of Arabidopsis AGENET Domain Containing Protein 3 (AGDP3) as a cellular factor that is required to prevent gene silencing and DNA hypermethylation. AGDP3 binds to H3K9me2 marks in its target DNA via its AGD12 cassette. Analysis of the crystal structure of the AGD12 cassette of AGDP3 in complex with an H3K9me2 peptide revealed that dimethylated H3K9 and unmodified H3K4 are specifically anchored into two different surface pockets. A histidine residue located in the methyllysine binding aromatic cage provides AGDP3 with pH-dependent H3K9me2 binding capacity. Our results uncover a molecular mechanism for the regulation of DNA demethylation by the gene silencing mark H3K9me2.
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Affiliation(s)
- Xuelin Zhou
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 201602, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Mengwei Wei
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 201602, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Wenfeng Nie
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 201602, China
- Department of Horticulture, College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, 225009, China
| | - Yue Xi
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 201602, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Li Peng
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 201602, China
| | - Qijie Zheng
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 201602, China
| | - Kai Tang
- Department of Horticulture & Landscape Architecture, Purdue University, West Lafayette, Idiana, 47906, USA
| | - Viswanathan Satheesh
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 201602, China
| | - Yuhua Wang
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Jinyan Luo
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 201602, China
| | - Xuan Du
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Rui Liu
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Zhenlin Yang
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Honggui La
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 201602, China
| | - Yingli Zhong
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 201602, China
- College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, 410128, China
| | - Yu Yang
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 201602, China
| | - Jian-Kang Zhu
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 201602, China
- Department of Horticulture & Landscape Architecture, Purdue University, West Lafayette, Idiana, 47906, USA
| | - Jiamu Du
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Mingguang Lei
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 201602, China
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Yu S, Zhang Z, Li J, Zhu Y, Yin Y, Zhang X, Dai Y, Zhang A, Li C, Zhu Y, Fan J, Ruan Y, Dong X. Genome-wide identification and characterization of lncRNAs in sunflower endosperm. BMC PLANT BIOLOGY 2022; 22:494. [PMID: 36271333 PMCID: PMC9587605 DOI: 10.1186/s12870-022-03882-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Accepted: 10/13/2022] [Indexed: 06/01/2023]
Abstract
BACKGROUND Long non-coding RNAs (lncRNAs), as important regulators, play important roles in plant growth and development. The expression and epigenetic regulation of lncRNAs remain uncharacterized generally in plant seeds, especially in the transient endosperm of the dicotyledons. RESULTS In this study, we identified 11,840 candidate lncRNAs in 12 day-after-pollination sunflower endosperm by analyzing RNA-seq data. These lncRNAs were evenly distributed in all chromosomes and had specific features that were distinct from mRNAs including tissue-specificity expression, shorter and fewer exons. By GO analysis of protein coding genes showing strong correlation with the lncRNAs, we revealed that these lncRNAs potential function in many biological processes of seed development. Additionally, genome-wide DNA methylation analyses revealed that the level of DNA methylation at the transcription start sites was negatively correlated with gene expression levels in lncRNAs. Finally, 36 imprinted lncRNAs were identified including 32 maternally expressed lncRNAs and four paternally expressed lncRNAs. In CG and CHG context, DNA methylation levels of imprinted lncRNAs in the upstream and gene body regions were slightly lower in the endosperm than that in embryo tissues, which indicated that the maternal demethylation potentially induce the paternally bias expression of imprinted lncRNAs in sunflower endosperm. CONCLUSION Our findings not only identified and characterized lncRNAs on a genome-wide scale in the development of sunflower endosperm, but also provide novel insights into the parental effects and epigenetic regulation of lncRNAs in dicotyledonous seeds.
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Affiliation(s)
- Shuai Yu
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China
| | - Zhichao Zhang
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China
| | - Jing Li
- School of Traditional Chinese Materia Medica, Shenyang Pharmaceutical University, Shenyang, China
| | - Yanbin Zhu
- State Key Laboratory of Maize Bio-Breeding, Shenyang, China
- State Key Laboratory of the Northeast Crop Genetics and Breeding, Shenyang, China
| | - Yanzhe Yin
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China
| | - Xiaoyu Zhang
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China
| | - Yuxin Dai
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China
| | - Ao Zhang
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China
| | - Cong Li
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China
| | - Yanshu Zhu
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China
| | - Jinjuan Fan
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China
| | - Yanye Ruan
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China
| | - Xiaomei Dong
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China.
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China.
- State Key Laboratory of Maize Bio-Breeding, Shenyang, China.
- State Key Laboratory of the Northeast Crop Genetics and Breeding, Shenyang, China.
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5
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Gahlaut V, Samtani H, Gautam T, Khurana P. Identification and Characterization of DNA Demethylase Genes and Their Association With Thermal Stress in Wheat (Triticum aestivum L.). Front Genet 2022; 13:894020. [PMID: 35938005 PMCID: PMC9355123 DOI: 10.3389/fgene.2022.894020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 06/13/2022] [Indexed: 12/05/2022] Open
Abstract
DNA demethylases (dMTases) are essential proteins in plants that regulate DNA methylation levels. The dMTase genes have been explored in a number of plant species, however, members of this family have not been reported in wheat. We identified 12 wheat dMTase genes divided into two subfamilies: repressor of silencing 1 (ROS1) and DEMETER-Like (DML). The TadMTases in the same subfamily or clade in the phylogenetic tree have similar gene structures, protein motifs, and domains. The promoter sequence contains multiple cis-regulatory elements (CREs) that respond to abiotic stress, hormones, and light, suggesting that the majority of TadMTase genes play a role in wheat growth, development, and stress response. The nuclear localization signals (NLSs), subcellular localization, and SRR motifs were also analyzed. The expression profile analyses revealed that TadMTase genes showed differential gene expression patterns in distinct developmental stages and tissues as well as under heat stress (HS). Furthermore, the qRT-PCR analysis revealed that TadMTase gene expression differed amongst wheat cultivars with varying degrees of HS tolerance. Overall, this work contributes to the understanding of the biological function of wheat dMTases and lays the foundation for future investigations.
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Affiliation(s)
- Vijay Gahlaut
- Department of Plant Molecular Biology, University of Delhi, New Delhi, India
- CSIR-Institute of Himalayan Bioresource Technology, Palampur, India
- *Correspondence: Vijay Gahlaut,
| | - Harsha Samtani
- Department of Plant Molecular Biology, University of Delhi, New Delhi, India
| | - Tinku Gautam
- Department of Genetics and Plant Breeding, Chaudhary Charan Singh University, Meerut, India
| | - Paramjit Khurana
- Department of Plant Molecular Biology, University of Delhi, New Delhi, India
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6
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Lu D, Zhai J, Xi M. Regulation of DNA Methylation During Plant Endosperm Development. Front Genet 2022; 13:760690. [PMID: 35222527 PMCID: PMC8867698 DOI: 10.3389/fgene.2022.760690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 01/17/2022] [Indexed: 11/21/2022] Open
Abstract
The endosperm is a vital storage tissue in plant seeds. It provides nutrients to the embryos or the seedlings during seed development and germination. Although the genetic information in the endosperm cannot be passed directly to the next generation, its inherited epigenetic marks affect gene expression and its development and, consequently, embryo and seed growth. DNA methylation is a major form of epigenetic modification that can be investigated to understand the epigenome changes during reproductive development. Therefore, it is of great significance to explore the effects of endosperm DNA methylation on crop yield and traits. In this review, we discuss the changes in DNA methylation and the resulting imprinted gene expression levels during plant endosperm development, as well as their effects on seed development.
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Affiliation(s)
- Dongdong Lu
- Key Laboratory of Forest Genetics and Biotechnology of Ministry of Education, Nanjing Forestry University, Nanjing, China
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
- Institute of Plant and Food Science, Southern University of Science and Technology, Shenzhen, China
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Southern University of Science and Technology, Shenzhen, China
| | - Jixian Zhai
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
- Institute of Plant and Food Science, Southern University of Science and Technology, Shenzhen, China
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Southern University of Science and Technology, Shenzhen, China
- *Correspondence: Jixian Zhai, ; Mengli Xi,
| | - Mengli Xi
- Key Laboratory of Forest Genetics and Biotechnology of Ministry of Education, Nanjing Forestry University, Nanjing, China
- *Correspondence: Jixian Zhai, ; Mengli Xi,
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7
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Zhang Z, Yu S, Li J, Zhu Y, Jiang S, Xia H, Zhou Y, Sun D, Liu M, Li C, Zhu Y, Ruan Y, Dong X. Epigenetic modifications potentially controlling the allelic expression of imprinted genes in sunflower endosperm. BMC PLANT BIOLOGY 2021; 21:570. [PMID: 34863098 PMCID: PMC8642925 DOI: 10.1186/s12870-021-03344-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 10/26/2021] [Indexed: 06/02/2023]
Abstract
BACKGROUND Genomic imprinting is an epigenetic phenomenon mainly occurs in endosperm of flowering plants. Genome-wide identification of imprinted genes have been completed in several dicot Cruciferous plant and monocot crops. RESULTS Here, we analyzed global patterns of allelic gene expression in developing endosperm of sunflower which belongs to the composite family. Totally, 691 imprinted loci candidates were identified in 12 day-after-pollination sunflower endosperm including 79 maternally expressed genes (MEG) and 596 paternally expressed genes (PEG), 6 maternally expressed noncoding RNAs (MNC) and 10 paternally expressed noncoding RNAs (PNC). And a clear clustering of imprinted genes throughout the rapeseed genome was identified. Generally, imprinting in sunflower is conserved within a species, but intraspecific variation also was detected. Limited loci in sunflower are imprinted in other several different species. The DNA methylation pattern around imprinted genes were investigated in embryo and endosperm tissues. In CG context, the imprinted genes were significantly associated with differential methylated regions exhibiting hypomethylation in endosperm and hypermethylation in embryo, which indicated that the maternal demethylation in CG context potentially induce the genomic imprinting in endosperm. CONCLUSION Our study would be helpful for understanding of genomic imprinting in plants and provide potential basis for further research in imprinting in sunflower.
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Affiliation(s)
- Zhichao Zhang
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China
| | - Shuai Yu
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China
| | - Jing Li
- School of Traditional Chinese Materia Medica, Shenyang Pharmaceutical University, Shenyang, China
| | - Yanbin Zhu
- State Key Laboratory of Maize Bio-Breeding, Shenyang, China
- State Key Laboratory of the Northeast Crop Genetics and Breeding, Shenyang, China
| | - Siqi Jiang
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China
| | - Haoran Xia
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China
| | - Yue Zhou
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China
| | - Daqiu Sun
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China
| | - Meiling Liu
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China
| | - Cong Li
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China
| | - Yanshu Zhu
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China
| | - Yanye Ruan
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China
| | - Xiaomei Dong
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China.
- Shenyang City Key Laboratory of Maize Genomic Selection Breeding, Shenyang, 110866, Liaoning, China.
- State Key Laboratory of Maize Bio-Breeding, Shenyang, China.
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8
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Li M, Cui Q, Zhang XQ, Hsieh TF. Epigenetic remodeling by DNA glycosylases during rice reproduction. MOLECULAR PLANT 2021; 14:1433-1435. [PMID: 34273566 DOI: 10.1016/j.molp.2021.07.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 07/12/2021] [Accepted: 07/14/2021] [Indexed: 06/13/2023]
Affiliation(s)
- Mingzhuo Li
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC 27695, USA; Plants for Human Health Institute, North Carolina State University, North Carolina Research Campus, Kannapolis, NC 28081, USA
| | - Qirui Cui
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC 27695, USA; Plants for Human Health Institute, North Carolina State University, North Carolina Research Campus, Kannapolis, NC 28081, USA
| | - Xiang-Qian Zhang
- College of Forestry and Landscape Architecture, South China Agricultural University, 510642 Guangzhou, China
| | - Tzung-Fu Hsieh
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC 27695, USA; Plants for Human Health Institute, North Carolina State University, North Carolina Research Campus, Kannapolis, NC 28081, USA.
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9
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Rong H, Yang W, Zhu H, Jiang B, Jiang J, Wang Y. Genomic imprinted genes in reciprocal hybrid endosperm of Brassica napus. BMC PLANT BIOLOGY 2021; 21:140. [PMID: 33726676 PMCID: PMC7968328 DOI: 10.1186/s12870-021-02908-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 02/28/2021] [Indexed: 05/06/2023]
Abstract
BACKGROUND Genomic imprinting results in the expression of parent-of-origin-specific alleles in the offspring. Brassica napus is an oil crop with research values in polyploidization. Identification of imprinted genes in B. napus will enrich the knowledge of genomic imprinting in dicotyledon plants. RESULTS In this study, we performed reciprocal crosses between B. napus L. cultivars Yangyou 6 (Y6) and Zhongshuang 11 (ZS11) to collect endosperm at 20 and 25 days after pollination (DAP) for RNA-seq. In total, we identified 297 imprinted genes, including 283 maternal expressed genes (MEGs) and 14 paternal expressed genes (PEGs) according to the SNPs between Y6 and ZS11. Only 36 genes (35 MEGs and 1 PEG) were continuously imprinted in 20 and 25 DAP endosperm. We found 15, 2, 5, 3, 10, and 25 imprinted genes in this study were also imprinted in Arabidopsis, rice, castor bean, maize, B. rapa, and other B. napus lines, respectively. Only 26 imprinted genes were specifically expressed in endosperm, while other genes were also expressed in root, stem, leaf and flower bud of B. napus. A total of 109 imprinted genes were clustered on rapeseed chromosomes. We found the LTR/Copia transposable elements (TEs) were most enriched in both upstream and downstream of the imprinted genes, and the TEs enriched around imprinted genes were more than non-imprinted genes. Moreover, the expression of 5 AGLs and 6 pectin-related genes in hybrid endosperm were significantly changed comparing with that in parent endosperm. CONCLUSION This research provided a comprehensive identification of imprinted genes in B. napus, and enriched the gene imprinting in dicotyledon plants, which would be useful in further researches on how gene imprinting regulates seed development.
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Affiliation(s)
- Hao Rong
- Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology, Yangzhou University, Yangzhou, 225009 China
| | - Wenjing Yang
- Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology, Yangzhou University, Yangzhou, 225009 China
| | - Haotian Zhu
- Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology, Yangzhou University, Yangzhou, 225009 China
| | - Bo Jiang
- Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology, Yangzhou University, Yangzhou, 225009 China
| | - Jinjin Jiang
- Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology, Yangzhou University, Yangzhou, 225009 China
| | - Youping Wang
- Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology, Yangzhou University, Yangzhou, 225009 China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou, 225009 China
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10
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Application of 5-Methylcytosine DNA Glycosylase to the Quantitative Analysis of DNA Methylation. Int J Mol Sci 2021; 22:ijms22031072. [PMID: 33499041 PMCID: PMC7865733 DOI: 10.3390/ijms22031072] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Revised: 01/14/2021] [Accepted: 01/20/2021] [Indexed: 02/03/2023] Open
Abstract
In higher eukaryotes DNA methylation is a prominent epigenetic mark important for chromatin structure and gene expression. Thus, profiling DNA methylation is important for predicting gene expressions associated with specific traits or diseases. DNA methylation is achieved by DNA methyltransferases and can be actively removed by specific enzymes in a replication-independent manner. DEMETER (DME) is a bifunctional 5-methylcytosine (5mC) DNA glycosylase responsible for active DNA demethylation that excises 5mC from DNA and cleaves a sugar-phosphate bond generating a single strand break (SSB). In this study, DME was used to analyze DNA methylation levels at specific epialleles accompanied with gain or loss of DNA methylation. DME treatment on genomic DNA generates SSBs in a nonsequence-specific fashion proportional to 5mC density, and thus DNA methylation levels can be easily measured when combined with the quantitative PCR (qPCR) method. The DME-qPCR analysis was applied to measure DNA methylation levels at the FWA gene in late-flowering Arabidopsis mutants and the CNR gene during fruit ripening in tomato. Differentially methylated epialleles were successfully distinguished corresponding to their expression levels and phenotypes. DME-qPCR is proven a simple yet effective method for quantitative DNA methylation analysis, providing advantages over current techniques based on methylation-sensitive restriction digestion.
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11
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Kumar S, Mohapatra T. Dynamics of DNA Methylation and Its Functions in Plant Growth and Development. FRONTIERS IN PLANT SCIENCE 2021; 12:596236. [PMID: 34093600 PMCID: PMC8175986 DOI: 10.3389/fpls.2021.596236] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 04/19/2021] [Indexed: 05/20/2023]
Abstract
Epigenetic modifications in DNA bases and histone proteins play important roles in the regulation of gene expression and genome stability. Chemical modification of DNA base (e.g., addition of a methyl group at the fifth carbon of cytosine residue) switches on/off the gene expression during developmental process and environmental stresses. The dynamics of DNA base methylation depends mainly on the activities of the writer/eraser guided by non-coding RNA (ncRNA) and regulated by the developmental/environmental cues. De novo DNA methylation and active demethylation activities control the methylation level and regulate the gene expression. Identification of ncRNA involved in de novo DNA methylation, increased DNA methylation proteins guiding DNA demethylase, and methylation monitoring sequence that helps maintaining a balance between DNA methylation and demethylation is the recent developments that may resolve some of the enigmas. Such discoveries provide a better understanding of the dynamics/functions of DNA base methylation and epigenetic regulation of growth, development, and stress tolerance in crop plants. Identification of epigenetic pathways in animals, their existence/orthologs in plants, and functional validation might improve future strategies for epigenome editing toward climate-resilient, sustainable agriculture in this era of global climate change. The present review discusses the dynamics of DNA methylation (cytosine/adenine) in plants, its functions in regulating gene expression under abiotic/biotic stresses, developmental processes, and genome stability.
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Affiliation(s)
- Suresh Kumar
- Division of Biochemistry, ICAR-Indian Agricultural Research Institute, New Delhi, India
- *Correspondence: Suresh Kumar, ; , orcid.org/0000-0002-7127-3079
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12
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N'Diaye A, Byrns B, Cory AT, Nilsen KT, Walkowiak S, Sharpe A, Robinson SJ, Pozniak CJ. Machine learning analyses of methylation profiles uncovers tissue-specific gene expression patterns in wheat. THE PLANT GENOME 2020; 13:e20027. [PMID: 33016606 DOI: 10.1002/tpg2.20027] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 01/24/2020] [Accepted: 04/12/2020] [Indexed: 06/11/2023]
Abstract
DNA methylation is a mechanism of epigenetic modification in eukaryotic organisms. Generally, methylation within genes promoter inhibits regulatory protein binding and represses transcription, whereas gene body methylation is associated with actively transcribed genes. However, it remains unclear whether there is interaction between methylation levels across genic regions and which site has the biggest impact on gene regulation. We investigated and used the methylation patterns of the bread wheat cultivar Chinese Spring to uncover differentially expressed genes (DEGs) between roots and leaves, using six machine learning algorithms and a deep neural network. As anticipated, genes with higher expression in leaves were mainly involved in photosynthesis and pigment biosynthesis processes whereas genes that were not differentially expressed between roots and leaves were involved in protein processes and membrane structures. Methylation occurred preponderantly (60%) in the CG context, whereas 35 and 5% of methylation occurred in CHG and CHH contexts, respectively. Methylation levels were highly correlated (r = 0.7 to 0.9) between all genic regions, except within the promoter (r = 0.4 to 0.5). Machine learning models gave a high (0.81) prediction accuracy of DEGs. There was a strong correlation (p-value = 9.20×10-10 ) between all features and gene expression, suggesting that methylation across all genic regions contribute to gene regulation. However, the methylation of the promoter, the CDS and the exon in CG context was the most impactful. Our study provides more insights into the interplay between DNA methylation and gene expression and paves the way for identifying tissue-specific genes using methylation profiles.
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Affiliation(s)
- Amidou N'Diaye
- Department of Plant Sciences and Crop Development Centre, University of Saskatchewan, Saskatoon, SK, Canada, S7N 5A8
| | - Brook Byrns
- Department of Plant Sciences and Crop Development Centre, University of Saskatchewan, Saskatoon, SK, Canada, S7N 5A8
| | - Aron T Cory
- Department of Plant Sciences and Crop Development Centre, University of Saskatchewan, Saskatoon, SK, Canada, S7N 5A8
| | - Kirby T Nilsen
- Department of Plant Sciences and Crop Development Centre, University of Saskatchewan, Saskatoon, SK, Canada, S7N 5A8
| | - Sean Walkowiak
- Department of Plant Sciences and Crop Development Centre, University of Saskatchewan, Saskatoon, SK, Canada, S7N 5A8
| | - Andrew Sharpe
- Global Institute for Food Security, Saskatoon, SK, Canada, S7N 0W9
| | - Stephen J Robinson
- Saskatoon Research and Development Centre, Agriculture and Agri-Food Canada, Saskatoon, SK, Canada, S7N 0X2
| | - Curtis J Pozniak
- Department of Plant Sciences and Crop Development Centre, University of Saskatchewan, Saskatoon, SK, Canada, S7N 5A8
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13
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Pasternak T, Lystvan K, Betekhtin A, Hasterok R. From Single Cell to Plants: Mesophyll Protoplasts as a Versatile System for Investigating Plant Cell Reprogramming. Int J Mol Sci 2020; 21:E4195. [PMID: 32545519 PMCID: PMC7348876 DOI: 10.3390/ijms21124195] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 06/07/2020] [Accepted: 06/10/2020] [Indexed: 01/24/2023] Open
Abstract
Plants are sessile organisms that have a remarkable developmental plasticity, which ensures their optimal adaptation to environmental stresses. Plant cell totipotency is an extreme example of such plasticity, whereby somatic cells have the potential to form plants via direct shoot organogenesis or somatic embryogenesis in response to various exogenous and/or endogenous signals. Protoplasts provide one of the most suitable systems for investigating molecular mechanisms of totipotency, because they are effectively single cell populations. In this review, we consider the current state of knowledge of the mechanisms that induce cell proliferation from individual, differentiated somatic plant cells. We highlight initial explant metabolic status, ploidy level and isolation procedure as determinants of successful cell reprogramming. We also discuss the importance of auxin signalling and its interaction with stress-regulated pathways in governing cell cycle induction and further stages of plant cell totipotency.
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Affiliation(s)
- Taras Pasternak
- Institute of Biology II/Molecular Plant Physiology, Centre for BioSystems Analysis, BIOSS Centre for Biological Signalling Studies University of Freiburg, 79104 Freiburg, Germany
| | - Kateryna Lystvan
- Institute of Cell Biology and Genetic Engineering of the National Academy of Sciences of Ukraine, 03143 Kyiv, Ukraine;
| | - Alexander Betekhtin
- Plant Cytogenetics and Molecular Biology Group, Institute of Biology, Biotechnology and Environmental Protection, Faculty of Natural Sciences, University of Silesia in Katowice, 40-032 Katowice, Poland;
| | - Robert Hasterok
- Plant Cytogenetics and Molecular Biology Group, Institute of Biology, Biotechnology and Environmental Protection, Faculty of Natural Sciences, University of Silesia in Katowice, 40-032 Katowice, Poland;
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14
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Grimanelli D, Ingouff M. DNA Methylation Readers in Plants. J Mol Biol 2020:S0022-2836(20)30027-9. [PMID: 31931004 DOI: 10.1016/j.jmb.2019.12.043] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 12/13/2019] [Accepted: 12/17/2019] [Indexed: 01/09/2023]
Abstract
In plants, DNA methylation occurs in distinct sequence contexts, including CG, CHG, and CHH. Thus, plants have developed a surprisingly diverse set of DNA methylation readers to cope with an extended repertoire of methylated sites. The Arabidopsis genome contains twelve Methyl-Binding Domain proteins (MBD), and nine SET and RING finger-associated (SRA) domain containing proteins belonging to the SUVH clade, in addition to three homologs of UHRF1, namely VIM1-3, all containing SRA domains. In this review, we will highlight several research questions that remain unresolved with respect to the function of plant DNA methylation readers, which can have both de novo demethylase and maintenance activity. We argue that maintenance of CG methylation in plants likely involved actors not found in their mammalian counterparts, and that new evidence suggests significant reprogramming of DNA methylation during plant reproduction as an important new development in the field.
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Affiliation(s)
- Daniel Grimanelli
- Institut de Recherche pour le Développement (IRD), Université de Montpellier, 911 Avenue Agropolis, 34394, Montpellier, France.
| | - Mathieu Ingouff
- Institut de Recherche pour le Développement (IRD), Université de Montpellier, 911 Avenue Agropolis, 34394, Montpellier, France.
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15
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Han Q, Bartels A, Cheng X, Meyer A, An YQC, Hsieh TF, Xiao W. Epigenetics Regulates Reproductive Development in Plants. PLANTS 2019; 8:plants8120564. [PMID: 31810261 PMCID: PMC6963493 DOI: 10.3390/plants8120564] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2019] [Revised: 11/23/2019] [Accepted: 11/27/2019] [Indexed: 12/20/2022]
Abstract
Seed, resulting from reproductive development, is the main nutrient source for human beings, and reproduction has been intensively studied through genetic, molecular, and epigenetic approaches. However, how different epigenetic pathways crosstalk and integrate to regulate seed development remains unknown. Here, we review the recent progress of epigenetic changes that affect chromatin structure, such as DNA methylation, polycomb group proteins, histone modifications, and small RNA pathways in regulating plant reproduction. In gametogenesis of flowering plants, epigenetics is dynamic between the companion cell and gametes. Cytosine DNA methylation occurs in CG, CHG, CHH contexts (H = A, C, or T) of genes and transposable elements, and undergoes dynamic changes during reproduction. Cytosine methylation in the CHH context increases significantly during embryogenesis, reaches the highest levels in mature embryos, and decreases as the seed germinates. Polycomb group proteins are important transcriptional regulators during seed development. Histone modifications and small RNA pathways add another layer of complexity in regulating seed development. In summary, multiple epigenetic pathways are pivotal in regulating seed development. It remains to be elucidated how these epigenetic pathways interplay to affect dynamic chromatin structure and control reproduction.
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Affiliation(s)
- Qiang Han
- Department of Biology, Saint Louis University, St. Louis, MO 63103, USA (A.B.); (X.C.)
| | - Arthur Bartels
- Department of Biology, Saint Louis University, St. Louis, MO 63103, USA (A.B.); (X.C.)
| | - Xi Cheng
- Department of Biology, Saint Louis University, St. Louis, MO 63103, USA (A.B.); (X.C.)
| | - Angela Meyer
- Department of Biology, Saint Louis University, St. Louis, MO 63103, USA (A.B.); (X.C.)
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA
| | - Yong-Qiang Charles An
- US Department of Agriculture, Agricultural Research Service, Midwest Area, Plant Genetics Research Unit, Donald Danforth Plant Science Center, MO 63132, USA;
| | - Tzung-Fu Hsieh
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC 27695, USA;
- Plants for Human Health Institute, North Carolina State University, North Carolina Research Campus, Kannapolis, NC 28081, USA
| | - Wenyan Xiao
- Department of Biology, Saint Louis University, St. Louis, MO 63103, USA (A.B.); (X.C.)
- Correspondence: ; Tel.: +1-314-977-2547
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16
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Parrilla-Doblas JT, Roldán-Arjona T, Ariza RR, Córdoba-Cañero D. Active DNA Demethylation in Plants. Int J Mol Sci 2019; 20:E4683. [PMID: 31546611 PMCID: PMC6801703 DOI: 10.3390/ijms20194683] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 09/17/2019] [Accepted: 09/19/2019] [Indexed: 02/06/2023] Open
Abstract
Methylation of cytosine (5-meC) is a critical epigenetic modification in many eukaryotes, and genomic DNA methylation landscapes are dynamically regulated by opposed methylation and demethylation processes. Plants are unique in possessing a mechanism for active DNA demethylation involving DNA glycosylases that excise 5-meC and initiate its replacement with unmodified C through a base excision repair (BER) pathway. Plant BER-mediated DNA demethylation is a complex process involving numerous proteins, as well as additional regulatory factors that avoid accumulation of potentially harmful intermediates and coordinate demethylation and methylation to maintain balanced yet flexible DNA methylation patterns. Active DNA demethylation counteracts excessive methylation at transposable elements (TEs), mainly in euchromatic regions, and one of its major functions is to avoid methylation spreading to nearby genes. It is also involved in transcriptional activation of TEs and TE-derived sequences in companion cells of male and female gametophytes, which reinforces transposon silencing in gametes and also contributes to gene imprinting in the endosperm. Plant 5-meC DNA glycosylases are additionally involved in many other physiological processes, including seed development and germination, fruit ripening, and plant responses to a variety of biotic and abiotic environmental stimuli.
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Affiliation(s)
- Jara Teresa Parrilla-Doblas
- Maimónides Biomedical Research Institute of Córdoba (IMIBIC), 14071 Córdoba, Spain.
- Department of Genetics, University of Córdoba, 14071 Córdoba, Spain.
- Reina Sofía University Hospital, 14071 Córdoba, Spain.
| | - Teresa Roldán-Arjona
- Maimónides Biomedical Research Institute of Córdoba (IMIBIC), 14071 Córdoba, Spain.
- Department of Genetics, University of Córdoba, 14071 Córdoba, Spain.
- Reina Sofía University Hospital, 14071 Córdoba, Spain.
| | - Rafael R Ariza
- Maimónides Biomedical Research Institute of Córdoba (IMIBIC), 14071 Córdoba, Spain.
- Department of Genetics, University of Córdoba, 14071 Córdoba, Spain.
- Reina Sofía University Hospital, 14071 Córdoba, Spain.
| | - Dolores Córdoba-Cañero
- Maimónides Biomedical Research Institute of Córdoba (IMIBIC), 14071 Córdoba, Spain.
- Department of Genetics, University of Córdoba, 14071 Córdoba, Spain.
- Reina Sofía University Hospital, 14071 Córdoba, Spain.
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17
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Abstract
DNA methylation is a conserved epigenetic modification that is important for gene regulation and genome stability. Aberrant patterns of DNA methylation can lead to plant developmental abnormalities. A specific DNA methylation state is an outcome of dynamic regulation by de novo methylation, maintenance of methylation and active demethylation, which are catalysed by various enzymes that are targeted by distinct regulatory pathways. In this Review, we discuss DNA methylation in plants, including methylating and demethylating enzymes and regulatory factors, and the coordination of methylation and demethylation activities by a so-called methylstat mechanism; the functions of DNA methylation in regulating transposon silencing, gene expression and chromosome interactions; the roles of DNA methylation in plant development; and the involvement of DNA methylation in plant responses to biotic and abiotic stress conditions.
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18
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Abstract
Flowering plants reproduce via a unique double-fertilization event, producing the zygote and the nutritive endosperm. The genome of the central cell, the precursor of the endosperm, undergoes extensive demethylation prior to fertilization. This epigenetic reconfiguration, directed by the DEMETER (DME) glycosylase at thousands of loci in Arabidopsis, differentiates the epigenetic landscapes of parental genomes and establishes parent of origin-specific expression of many imprinted genes in endosperm essential for seed development. However, how DME is targeted to various locations remains unknown. Here we show that the multidomain DME is organized into 2 functional regions: the C-terminal region, which guides localization and catalysis, and the N-terminal region, which likely recruits chromatin remodelers to facilitate demethylation within heterochromatin. The Arabidopsis DEMETER (DME) DNA glycosylase demethylates the maternal genome in the central cell prior to fertilization and is essential for seed viability. DME preferentially targets small transposons that flank coding genes, influencing their expression and initiating plant gene imprinting. DME also targets intergenic and heterochromatic regions, but how it is recruited to these differing chromatin landscapes is unknown. The C-terminal half of DME consists of 3 conserved regions required for catalysis in vitro. We show that this catalytic core guides active demethylation at endogenous targets, rescuing dme developmental and genomic hypermethylation phenotypes. However, without the N terminus, heterochromatin demethylation is significantly impeded, and abundant CG-methylated genic sequences are ectopically demethylated. Comparative analysis revealed that the conserved DME N-terminal domains are present only in flowering plants, whereas the domain architecture of DME-like proteins in nonvascular plants mainly resembles the catalytic core, suggesting that it might represent the ancestral form of the 5mC DNA glycosylase found in plant lineages. We propose a bipartite model for DME protein action and suggest that the DME N terminus was acquired late during land plant evolution to improve specificity and facilitate demethylation at heterochromatin targets.
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19
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Liu J, Li J, Liu HF, Fan SH, Singh S, Zhou XR, Hu ZY, Wang HZ, Hua W. Genome-wide screening and analysis of imprinted genes in rapeseed (Brassica napus L.) endosperm. DNA Res 2019; 25:629-640. [PMID: 30272113 PMCID: PMC6289790 DOI: 10.1093/dnares/dsy030] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 08/09/2018] [Indexed: 12/28/2022] Open
Abstract
Species-specific genomic imprinting is an epigenetic phenomenon leading to parent-of-origin-specific differential expression of maternally and paternally inherited alleles. To date, no studies of imprinting have been reported in rapeseed, a tetraploid species. Here, we analysed global patterns of allelic gene expression in developing rapeseed endosperms from reciprocal crosses between inbred lines YN171 and 93275. A total of 183 imprinted genes, consisting of 167 maternal expressed genes (MEGs) and 16 paternal expressed genes (PEGs), were identified from 14,394 genes found to harbour diagnostic SNPs between the parental lines. Some imprinted genes were validated in different endosperm stages and other parental combinations by RT-PCR analysis. A clear clustering of imprinted genes throughout the rapeseed genome was identified, which was different from most other plants. Methylation analysis of 104 out of the 183 imprinted genes showed that 11 genes (7 MEGs and 4 PEGs) harboured differentially methylated regions (DMRs). Unexpectedly, only 1 MEG out of these 11 genes had a DMR that exhibited high CG methylation rate in paternal allele and had big difference between parent alleles. These results extend our understanding of gene imprinting in plants and provide potential avenues for further research in imprinted genes.
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Affiliation(s)
- Jing Liu
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan, P.R. China
| | - Jun Li
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan, P.R. China
| | - Hong-Fang Liu
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan, P.R. China
| | - Shi-Hang Fan
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan, P.R. China
| | - Surinder Singh
- Agriculture and Food Commonwealth Scientific and Industrial Research Organization, Canberra, ACT, Australia
| | - Xue-Rong Zhou
- Agriculture and Food Commonwealth Scientific and Industrial Research Organization, Canberra, ACT, Australia
| | - Zhi-Yong Hu
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan, P.R. China
| | - Han-Zhong Wang
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan, P.R. China
| | - Wei Hua
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan, P.R. China
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20
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Agrelius T, Dudycha JL, Morris JT. Global DNA cytosine methylation variation in Spartina alterniflora at North Inlet, SC. PLoS One 2018; 13:e0203230. [PMID: 30199541 PMCID: PMC6130869 DOI: 10.1371/journal.pone.0203230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2018] [Accepted: 08/16/2018] [Indexed: 11/26/2022] Open
Abstract
Spartina alterniflora, marsh grass, is a vegetative apomicticly-reproducing halophyte native to marshes along the east coast of the United States and invasive across the world. S. alterniflora provides many ecosystem services including, but not limited to, water filtration, habitats for invertebrates, and sediment retention. Widespread diebacks of longstanding marsh grass colonies launched extensive investigations into probable mechanisms leading to patchy diebacks. There is still current debate as to the causes of a marsh dieback but environmental stress is acknowledged as a constant. Spatial epigenetic variation could contribute to variation of stress susceptibility, but the scale and structure of epigenetic variation is unknown. The current study investigates patterns of epigenetic variation in a natural population of S. alterniflora. This study examines variation of global DNA methylation within and among clones of the marsh grass Spartina alterniflora using an ELISA-like microplate reaction and observed significant heterogeneity of global DNA methylation within and among clones of S. alterniflora across the North Inlet basin, as well as significant differences of global methylation between adults and sexually produced seedlings. The present study also characterized differences for plants in a section of the population that experienced an acute marsh dieback in the year 2001 and have subsequently recolonized, finding a significant positive correlation between cytosine methylation and time period of colonization. The significant heterogeneity of global DNA methylation both within and among clones observed within this natural population of S. alterniflora and potential impacts from hypersaline environments at North Inlet suggests the need for more in-depth epigenetic studies to fully understand DNA methylation within an ecological context. Future studies should consider the effects of varying saline conditions on both global DNA and gene specific methylation.
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Affiliation(s)
- Trenton Agrelius
- Belle W. Baruch Institute for Marine and Coastal Sciences, University of South Carolina, Columbia, South Carolina, United States of America
- Department of Biological Sciences, University of South Carolina, Columbia, South Carolina, United States of America
- * E-mail:
| | - Jeffry L. Dudycha
- Department of Biological Sciences, University of South Carolina, Columbia, South Carolina, United States of America
| | - James T. Morris
- Belle W. Baruch Institute for Marine and Coastal Sciences, University of South Carolina, Columbia, South Carolina, United States of America
- Department of Biological Sciences, University of South Carolina, Columbia, South Carolina, United States of America
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21
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Erdmann RM, Satyaki PRV, Klosinska M, Gehring M. A Small RNA Pathway Mediates Allelic Dosage in Endosperm. Cell Rep 2018; 21:3364-3372. [PMID: 29262317 DOI: 10.1016/j.celrep.2017.11.078] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 09/18/2017] [Accepted: 11/21/2017] [Indexed: 12/12/2022] Open
Abstract
Balance between maternal and paternal genomes within the triploid endosperm is necessary for normal seed development. The majority of endosperm genes are expressed in a 2:1 maternal:paternal ratio, reflecting genomic DNA content. Here, we find that the 2:1 transcriptional ratio is, unexpectedly, actively regulated. In A. thaliana and A. lyrata, endosperm 24-nt small RNAs are reduced in transposable elements and enriched in genes compared with the embryo. We find an inverse relationship between the parent of origin of sRNAs and mRNAs, with genes more likely to be associated with maternally than paternally biased sRNAs. Disruption of the Pol IV sRNA pathway causes a shift toward maternal allele mRNA expression for many genes. Furthermore, paternal inheritance of an RNA Pol IV mutation is sufficient to rescue seed abortion caused by excess paternal genome dosage. Thus, RNA Pol IV mediates the transcriptional balance between maternally and paternally inherited genomes in endosperm.
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Affiliation(s)
- Robert M Erdmann
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | | | - Maja Klosinska
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Mary Gehring
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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22
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Dong X, Chen J, Li T, Li E, Zhang X, Zhang M, Song W, Zhao H, Lai J. Parent-of-origin-dependent nucleosome organization correlates with genomic imprinting in maize. Genome Res 2018; 28:1020-1028. [PMID: 29903724 PMCID: PMC6028132 DOI: 10.1101/gr.230201.117] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2017] [Accepted: 05/31/2018] [Indexed: 12/23/2022]
Abstract
Genomic imprinting refers to allele-specific expression of genes depending on their parental origin. Nucleosomes, the fundamental units of chromatin, play a critical role in gene transcriptional regulation. However, it remains unknown whether differential nucleosome organization is related to the allele-specific expression of imprinted genes. Here, we generated a genome-wide map of allele-specific nucleosome occupancy in maize endosperm and presented an integrated analysis of its relationship with parent-of-origin-dependent gene expression and DNA methylation. We found that ∼2.3% of nucleosomes showed significant parental bias in maize endosperm. The parent-of-origin-dependent nucleosomes mostly exist as single isolated nucleosomes. Parent-of-origin-dependent nucleosomes were significantly associated with the allele-specific expression of imprinted genes, with nucleosomes positioned preferentially in the promoter of nonexpressed alleles of imprinted genes. Furthermore, we found that most of the paternal specifically positioned nucleosomes (pat-nucleosomes) were associated with parent-of-origin-dependent differential methylated regions, suggesting a functional link between the maternal demethylation and the occurrence of pat-nucleosome. Maternal specifically positioned nucleosomes (mat-nucleosomes) were independent of allele-specific DNA methylation but seem to be associated with allele-specific histone modification. Our study provides the first genome-wide map of allele-specific nucleosome occupancy in plants and suggests a mechanistic connection between chromatin organization and genomic imprinting.
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Affiliation(s)
- Xiaomei Dong
- State Key Laboratory of Agrobiotechnology and National Maize Improvement Center, Department of Plant Genetics and Breeding, China Agricultural University, Beijing, 100193, People's Republic of China
| | - Jian Chen
- State Key Laboratory of Agrobiotechnology and National Maize Improvement Center, Department of Plant Genetics and Breeding, China Agricultural University, Beijing, 100193, People's Republic of China
| | - Tong Li
- State Key Laboratory of Agrobiotechnology and National Maize Improvement Center, Department of Plant Genetics and Breeding, China Agricultural University, Beijing, 100193, People's Republic of China
| | - En Li
- State Key Laboratory of Agrobiotechnology and National Maize Improvement Center, Department of Plant Genetics and Breeding, China Agricultural University, Beijing, 100193, People's Republic of China
| | - Xiangbo Zhang
- State Key Laboratory of Agrobiotechnology and National Maize Improvement Center, Department of Plant Genetics and Breeding, China Agricultural University, Beijing, 100193, People's Republic of China
| | - Mei Zhang
- State Key Laboratory of Agrobiotechnology and National Maize Improvement Center, Department of Plant Genetics and Breeding, China Agricultural University, Beijing, 100193, People's Republic of China.,Department of Biology, Stanford University, Stanford, California 94305, USA
| | - Weibin Song
- State Key Laboratory of Agrobiotechnology and National Maize Improvement Center, Department of Plant Genetics and Breeding, China Agricultural University, Beijing, 100193, People's Republic of China
| | - Haiming Zhao
- State Key Laboratory of Agrobiotechnology and National Maize Improvement Center, Department of Plant Genetics and Breeding, China Agricultural University, Beijing, 100193, People's Republic of China
| | - Jinsheng Lai
- State Key Laboratory of Agrobiotechnology and National Maize Improvement Center, Department of Plant Genetics and Breeding, China Agricultural University, Beijing, 100193, People's Republic of China.,Center for Crop Functional Genomics and Molecular Breeding, China Agricultural University, Beijing, 100193, People's Republic of China
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Kong W, Li B, Wang Q, Wang B, Duan X, Ding L, Lu Y, Liu LW, La H. Analysis of the DNA methylation patterns and transcriptional regulation of the NB-LRR-encoding gene family in Arabidopsis thaliana. PLANT MOLECULAR BIOLOGY 2018; 96:563-575. [PMID: 29525832 DOI: 10.1007/s11103-018-0715-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Accepted: 03/02/2018] [Indexed: 05/26/2023]
Abstract
The relationships between transcription and methylation were revealed in Arabidopsis thaliana NB-LRR-encoding genes in wild type (Col-0) and different mutants. Plant nucleotide-binding, leucine-rich repeat (NB-LRR) proteins constitute a large family that plays predominant roles in disease resistance. However, the regulation of NB-LRR-encoding genes at the transcriptional level is still poorly understood. Recently, DNA cytosine methylation in eukaryotes has been described as serving an important function in regulating gene expression. Here, we analysed the DNA methylation patterns of NB-LRR-encoding genes in Arabidopsis thaliana in samples from a wild type (Col-0) and ago4, met1, cmt3, drm1/2, and ddm1 mutants. Our results revealed that the vast majority of the NB-LRR-encoding genes in Col-0 were methylated, and the DNA methylation occurred predominantly in the CG sequence context. Moreover, DNA methylation was widely distributed in both the promoters and the bodies of most NB-LRR-encoding genes. Our results also showed that the loss of AGO4, MET1, CMT3, DRM1/2 or DDM1 functions generally led to decreased cytosine methylation in the NB-LRR-encoding genes. Analysis of the available transcriptome data from the wild type and the met1, cmt3, drm1/2 and ddm1 mutants revealed that differences in the transcription levels between the wild type and mutants were statistically significant for 63 of the NB-LRR-encoding genes. Of these genes, 38 were significantly upregulated, and the other 25 were significantly downregulated. Some NB-LRR-encoding genes with differential expression levels, which were revealed by the mRNA-Seq data, were confirmed to be significantly upregulated or downregulated in the mutants compared to the wild type by using quantitative RT-PCR. These data suggest that some Arabidopsis NB-LRR-encoding genes are likely to be regulated by altered DNA methylation patterns.
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Affiliation(s)
- Weiwen Kong
- School of Horticulture and Plant Protection, Yangzhou University, Yangzhou, 225009, Jiangsu, China.
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education, Yangzhou University, Yangzhou, 225009, Jiangsu, China.
| | - Bin Li
- School of Horticulture and Plant Protection, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Qianqian Wang
- College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China
| | - Bin Wang
- School of Horticulture and Plant Protection, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Xiaoke Duan
- College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China
| | - Li Ding
- School of Horticulture and Plant Protection, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Yanke Lu
- College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China
| | - Li-Wei Liu
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, 210023, China
| | - Honggui La
- College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China.
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Ding CJ, Liang LX, Diao S, Su XH, Zhang BY. Genome-wide analysis of day/night DNA methylation differences in Populus nigra. PLoS One 2018; 13:e0190299. [PMID: 29293569 PMCID: PMC5749751 DOI: 10.1371/journal.pone.0190299] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 12/12/2017] [Indexed: 12/19/2022] Open
Abstract
DNA methylation is an important mechanism of epigenetic modification. Methylation changes during stress responses and developmental processes have been well studied; however, their role in plant adaptation to the day/night cycle is poorly understood. In this study, we detected global methylation patterns in leaves of the black poplar Populus nigra ‘N46’ at 8:00 and 24:00 by methylated DNA immunoprecipitation sequencing (MeDIP-seq). We found 10,027 and 10,242 genes to be methylated in the 8:00 and 24:00 samples, respectively. The methylated genes appeared to be involved in multiple biological processes, molecular functions, and cellular components, suggesting important roles for DNA methylation in poplar cells. Comparing the 8:00 and 24:00 samples, only 440 differentially methylated regions (DMRs) overlapped with genic regions, including 193 hyper- and 247 hypo-methylated DMRs, and may influence the expression of 137 downstream genes. Most hyper-methylated genes were associated with transferase activity, kinase activity, and phosphotransferase activity, whereas most hypo-methylated genes were associated with protein binding, ATP binding, and adenyl ribonucleotide binding, suggesting that different biological processes were activated during the day and night. Our results indicated that methylated genes were prevalent in the poplar genome, but that only a few of these participated in diurnal gene expression regulation.
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Affiliation(s)
- Chang-Jun Ding
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
- Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
| | - Li-Xiong Liang
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
- Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
| | - Shu Diao
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
- Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
| | - Xiao-Hua Su
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
- Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
| | - Bing-Yu Zhang
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
- Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
- * E-mail:
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25
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DEMETER plant DNA demethylase induces antiviral response by interferon signalling in animal cells. Sci Rep 2017; 7:9160. [PMID: 28831075 PMCID: PMC5567224 DOI: 10.1038/s41598-017-08827-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 07/17/2017] [Indexed: 12/20/2022] Open
Abstract
DNA methylation is a prominent epigenetic modification in plants and animals regulated by similar mechanisms but the process of DNA demethylation is profoundly different. Unlike vertebrates that require a series of enzymatic conversions of 5-methylcytosine (5mC) into other bases for DNA demethylation, plants utilize the DEMETER (DME) family of 5mC DNA glycosylases to catalyze a direct removal of 5mC from DNA. Here we introduced Arabidopsis DME into human HEK-293T cells to allow direct 5mC excision, and observed that direct DNA demethylation activity was successfully implemented by DME expression. In addition, DME induced diverse cellular responses such as cell proliferation inhibition, cell cycle dysregulation and S phase arrest. Microarray and methylome analyses revealed that DME upregulated a number of genes including cell cycle components, heat shock proteins, and notably, various interferon-stimulated genes. Moreover, DME-mediated DNA demethylation activated endogenous repeat elements, which are likely to form dsRNAs as viral mimics and eventually trigger interferon cascades to establish the antiviral state. This work demonstrates that plant DNA demethylase catalyzes DNA demethylation with a bypass of initial base conversion steps, and the interferon signaling plays a pivotal role to alleviate genotoxic stresses associated with DME-induced DNA demethylation in mammalian cells.
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Dong X, Zhang M, Chen J, Peng L, Zhang N, Wang X, Lai J. Dynamic and Antagonistic Allele-Specific Epigenetic Modifications Controlling the Expression of Imprinted Genes in Maize Endosperm. MOLECULAR PLANT 2017; 10:442-455. [PMID: 27793787 DOI: 10.1016/j.molp.2016.10.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 10/10/2016] [Accepted: 10/10/2016] [Indexed: 05/22/2023]
Abstract
Genomic imprinting is often associated with allele-specific epigenetic modifications. Although many reports suggested potential roles of DNA methylation and H3K27me3 in regulating genomic imprinting, the contributions of allele-specific active histone modifications to imprinting remain still unclear in plants. Here, we report the identification of 337 high-stringency allele-specific H3K4me3 and H3K36me3 peaks in maize endosperm. Paternally preferred H3K4me3 and H3K36me3 peaks mostly co-localized with paternally expressed genes (PEGs), while endosperm-specific maternally expressed genes (endo-MEGs) were associated with maternally preferred H3K4me3 and H3K36me3 peaks. A unique signature for PEGs was observed, where the active H3K4me4 and H3K36me3 as well as repressive H3K27me3 appeared together. At the gene body of con-PEGs (constitutively expressed PEG), H3K27me3 and H3K36me3 were specifically deposited on hypomethylated maternal alleles and hypermethylated paternal alleles, respectively. Around the transcription start sites of endo-MEGs, DNA methylation and H3K4me3 specifically marked paternal and maternal alleles, respectively. In addition, 35 maternally expressed non-coding RNAs exhibited the same allele-specific epigenetic features as endo-MEGs, indicating similar mechanisms for the regulation of imprinted genes and non-coding RNAs. Taken together, our results uncover the complex patterns of mutually exclusive epigenetic modifications deposited at different alleles of imprinted genes that are required for genomic imprinting in maize endosperm.
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Affiliation(s)
- Xiaomei Dong
- State Key Laboratory of Agrobiotechnology and National Maize Improvement Center, Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, P.R. China
| | - Mei Zhang
- State Key Laboratory of Agrobiotechnology and National Maize Improvement Center, Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, P.R. China; Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Jian Chen
- State Key Laboratory of Agrobiotechnology and National Maize Improvement Center, Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, P.R. China
| | - Lizeng Peng
- State Key Laboratory of Agrobiotechnology and National Maize Improvement Center, Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, P.R. China
| | - Nan Zhang
- State Key Laboratory of Agrobiotechnology and National Maize Improvement Center, Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, P.R. China
| | - Xin Wang
- State Key Laboratory of Agrobiotechnology and National Maize Improvement Center, Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, P.R. China
| | - Jinsheng Lai
- State Key Laboratory of Agrobiotechnology and National Maize Improvement Center, Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, P.R. China.
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Lu C, Yu F, Tian L, Huang X, Tan H, Xie Z, Hao X, Li D, Luan S, Chen L. RPS9M, a Mitochondrial Ribosomal Protein, Is Essential for Central Cell Maturation and Endosperm Development in Arabidopsis. FRONTIERS IN PLANT SCIENCE 2017; 8:2171. [PMID: 29312411 PMCID: PMC5744018 DOI: 10.3389/fpls.2017.02171] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2017] [Accepted: 12/11/2017] [Indexed: 05/15/2023]
Abstract
During double fertilization of angiosperms, the central cell of the female gametophyte fuses with a sperm cell to produce the endosperm, a storage tissue that nourishes the developing embryo within the seed. Although many genetic mutants defective in female gametophytic functions have been characterized, the molecular mechanisms controlling the specification and differentiation of the central cell are still not fully understood. Here, we report a mitochondrial ribosomal protein, RPS9M, is required for central cell maturation. RPS9M was highly expressed in the male and female gametophytes before and after double fertilization. The female gametophytes were defective in the rps9m mutant specifically concerning maturation of central cells. The morphological defects include unfused polar nuclei and smaller central vacuole in central cells. In addition, embryo initiation and early endosperm development were also severely affected in rps9m female gametophytes even after fertilized with wild type pollens. The RPS9M can interact with ANK6, an ankyrin-repeat protein in mitochondria previously reported to be required for fertilization. The expression pattern and mutant phenotype of RPS9M are similar to those of ANK6 as well, suggesting that RPS9M may work together with ANK6 in controlling female gametophyte development, possibly by regulating the expression of some mitochondrial proteins.
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Affiliation(s)
- Changqing Lu
- Hunan Province Key Laboratory of Crop Sterile Germplasm Resource Innovation and Application, Hunan Normal University, Changsha, China
| | - Feng Yu
- Hunan Province Key Laboratory of Crop Sterile Germplasm Resource Innovation and Application, Hunan Normal University, Changsha, China
| | - Lianfu Tian
- Hunan Province Key Laboratory of Crop Sterile Germplasm Resource Innovation and Application, Hunan Normal University, Changsha, China
| | - Xiaoying Huang
- Hunan Province Key Laboratory of Crop Sterile Germplasm Resource Innovation and Application, Hunan Normal University, Changsha, China
| | - Hong Tan
- Hunan Province Key Laboratory of Crop Sterile Germplasm Resource Innovation and Application, Hunan Normal University, Changsha, China
| | - Zijing Xie
- Hunan Province Key Laboratory of Crop Sterile Germplasm Resource Innovation and Application, Hunan Normal University, Changsha, China
| | - Xiaohua Hao
- Hunan Province Key Laboratory of Crop Sterile Germplasm Resource Innovation and Application, Hunan Normal University, Changsha, China
| | - Dongping Li
- Hunan Province Key Laboratory of Crop Sterile Germplasm Resource Innovation and Application, Hunan Normal University, Changsha, China
- *Correspondence: Dongping Li, Sheng Luan, Liangbi Chen,
| | - Sheng Luan
- Hunan Province Key Laboratory of Crop Sterile Germplasm Resource Innovation and Application, Hunan Normal University, Changsha, China
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA, United States
- *Correspondence: Dongping Li, Sheng Luan, Liangbi Chen,
| | - Liangbi Chen
- Hunan Province Key Laboratory of Crop Sterile Germplasm Resource Innovation and Application, Hunan Normal University, Changsha, China
- *Correspondence: Dongping Li, Sheng Luan, Liangbi Chen,
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28
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Lebedeva MA, Tvorogova VE, Tikhodeyev ON. Epigenetic mechanisms and their role in plant development. RUSS J GENET+ 2016. [DOI: 10.1134/s1022795417090083] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Abstract
Genomic imprinting, an inherently epigenetic phenomenon defined by parent of origin-dependent gene expression, is observed in mammals and flowering plants. Genome-scale surveys of imprinted expression and the underlying differential epigenetic marks have led to the discovery of hundreds of imprinted plant genes and confirmed DNA and histone methylation as key regulators of plant imprinting. However, the biological roles of the vast majority of imprinted plant genes are unknown, and the evolutionary forces shaping plant imprinting remain rather opaque. Here, we review the mechanisms of plant genomic imprinting and discuss theories of imprinting evolution and biological significance in light of recent findings.
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Affiliation(s)
- Jessica A Rodrigues
- Department of Plant and Microbial Biology, University of California at Berkeley, Berkeley, California 94720, USA
| | - Daniel Zilberman
- Department of Plant and Microbial Biology, University of California at Berkeley, Berkeley, California 94720, USA
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30
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Abstract
Environmental conditions can change the activity of plant genes via epigenetic effects that alter the competence of genetic information to be expressed. This may provide a powerful strategy for plants to adapt to environmental change. However, as epigenetic changes do not modify DNA sequences and are therefore reversible, only those epi-mutations that are transmitted through the germline can be expected to contribute to a long-term adaptive response. The major challenge for the investigation of epigenetic adaptation theories is therefore to identify genomic loci that undergo epigenetic changes in response to environmental conditions, which alter their expression in a heritable way and which improve the plant's ability to adapt to the inducing conditions. This review focuses on the role of DNA methylation as a prominent epigenetic mark that controls chromatin conformation, and on its potential in mediating expression changes in response to environmental signals.
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Affiliation(s)
- Peter Meyer
- Centre for Plant Sciences, University of Leeds, Leeds, UK
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31
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Mei X, Liu C, Yu T, Liu X, Xu D, Wang J, Wang G, Cai Y. Identification and characterization of paternal-preferentially expressed gene NF-YC8 in maize endosperm. Mol Genet Genomics 2015; 290:1819-31. [DOI: 10.1007/s00438-015-1043-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2015] [Accepted: 03/28/2015] [Indexed: 01/17/2023]
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32
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Jeong CW, Park GT, Yun H, Hsieh TF, Choi YD, Choi Y, Lee JS. Control of Paternally Expressed Imprinted UPWARD CURLY LEAF1, a Gene Encoding an F-Box Protein That Regulates CURLY LEAF Polycomb Protein, in the Arabidopsis Endosperm. PLoS One 2015; 10:e0117431. [PMID: 25689861 PMCID: PMC4331533 DOI: 10.1371/journal.pone.0117431] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 12/22/2014] [Indexed: 12/22/2022] Open
Abstract
Genomic imprinting, an epigenetic process in mammals and flowering plants, refers to the differential expression of alleles of the same genes in a parent-of-origin-specific manner. In Arabidopsis, imprinting occurs primarily in the endosperm, which nourishes the developing embryo. Recent high-throughput sequencing analyses revealed that more than 200 loci are imprinted in Arabidopsis; however, only a few of these imprinted genes and their imprinting mechanisms have been examined in detail. Whereas most imprinted loci characterized to date are maternally expressed imprinted genes (MEGs), PHERES1 (PHE1) and ADMETOS (ADM) are paternally expressed imprinted genes (PEGs). Here, we report that UPWARD CURLY LEAF1 (UCL1), a gene encoding an E3 ligase that degrades the CURLY LEAF (CLF) polycomb protein, is a PEG. After fertilization, paternally inherited UCL1 is expressed in the endosperm, but not in the embryo. The expression pattern of a β-glucuronidase (GUS) reporter gene driven by the UCL1 promoter suggests that the imprinting control region (ICR) of UCL1 is adjacent to a transposable element in the UCL1 5′-upstream region. Polycomb Repressive Complex 2 (PRC2) silences the maternal UCL1 allele in the central cell prior to fertilization and in the endosperm after fertilization. The UCL1 imprinting pattern was not affected in paternal PRC2 mutants. We found unexpectedly that the maternal UCL1 allele is reactivated in the endosperm of Arabidopsis lines with mutations in cytosine DNA METHYLTRANSFERASE 1 (MET1) or the DNA glycosylase DEMETER (DME), which antagonistically regulate CpG methylation of DNA. By contrast, maternal UCL1 silencing was not altered in mutants with defects in non-CpG methylation. Thus, silencing of the maternal UCL1 allele is regulated by both MET1 and DME as well as by PRC2, suggesting that divergent mechanisms for the regulation of PEGs evolved in Arabidopsis.
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Affiliation(s)
- Cheol Woong Jeong
- School of Biological Sciences, Seoul National University, Seoul, Korea
| | - Guen Tae Park
- School of Biological Sciences, Seoul National University, Seoul, Korea
| | - Hyein Yun
- School of Biological Sciences, Seoul National University, Seoul, Korea
| | - Tzung-Fu Hsieh
- Plants for Human Health Institute & Department of Plant and Microbial Biology, North Carolina State University, Kannapolis, North Carolina, United State of America
| | - Yang Do Choi
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Korea
| | - Yeonhee Choi
- School of Biological Sciences, Seoul National University, Seoul, Korea
- * E-mail: (YC); (JSL)
| | - Jong Seob Lee
- School of Biological Sciences, Seoul National University, Seoul, Korea
- * E-mail: (YC); (JSL)
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Wang P, Xia H, Zhang Y, Zhao S, Zhao C, Hou L, Li C, Li A, Ma C, Wang X. Genome-wide high-resolution mapping of DNA methylation identifies epigenetic variation across embryo and endosperm in Maize (Zea may). BMC Genomics 2015; 16:21. [PMID: 25612809 PMCID: PMC4316406 DOI: 10.1186/s12864-014-1204-7] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 12/24/2014] [Indexed: 12/26/2022] Open
Abstract
Background Epigenetic modifications play important roles in plant and animal development. DNA methylation impacts the transposable element (TE) silencing, gene imprinting and expression regulation. Results Through a genome-wide analysis, DNA methylation peaks were characterized and mapped in maize embryo and endosperm genome, respectively. Distinct methylation level was observed across maize embryo and endosperm. The maize embryo genome contained more DNA methylation than endosperm. Totally, 985,478 CG islands (CGIs) were identified and most of them were unmethylated. More CGI shores were methylated than CGIs in maize suggested that DNA methylation level was not positively correlated with CpG density. The promoter sequence and transcriptional termination region (TTR) were more methylated than the gene body (intron and exon) region based on peak number and methylated depth. Result showed that 99% TEs were methylated in maize embryo, but a large portion of them (34.8%) were not methylated in endosperm. Maize embryo and endosperm exhibit distinct pattern/level of methylation. The most differentially methylated region between embryo and endosperm are CGI shores. Our results indicated that DNA methylation is associated with both gene silencing and gene activation in maize. Many genes involved in embryogenesis and seed development were found differentially methylated in embryo and endosperm. We found 41.5% imprinting genes were similarly methylated and 58.5% imprinting genes were differentially methylated between embryo and endosperm. Methylation level was associated with allelic silencing of only a small number of imprinting genes. The expression of maize DEMETER-like (DME-like) gene and MBD101 gene (MBD4 homolog) were higher in endosperm than in embryo. These two genes may be associated with distinct methylation levels across maize embryo and endosperm. Conclusions Through MeDIP-seq we systematically analyzed the methylomes of maize embryo and endosperm and results indicated that the global methylation status of embryo was more than that of the endosperm. Differences could be observed at the total number of methylation peaks, DMRs and specific methylated genes which were tightly associated with development of embryo and endosperm. Our results also revealed that many DNA methylation regions didn’t affect transcription of the corresponding genes. Electronic supplementary material The online version of this article (doi:10.1186/s12864-014-1204-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Pengfei Wang
- Agricultural College, Anhui Agricultural University, Hefei, 230036, PR China. .,Bio-Tech Research Center, Shandong Academy of Agricultural Sciences; Shandong Provincial Key Laboratory of Crop Genetic Improvement, Ecology and Physiology, Jinan, 250100, PR China.
| | - Han Xia
- Bio-Tech Research Center, Shandong Academy of Agricultural Sciences; Shandong Provincial Key Laboratory of Crop Genetic Improvement, Ecology and Physiology, Jinan, 250100, PR China.
| | - Ye Zhang
- Bio-Tech Research Center, Shandong Academy of Agricultural Sciences; Shandong Provincial Key Laboratory of Crop Genetic Improvement, Ecology and Physiology, Jinan, 250100, PR China.
| | - Shuzhen Zhao
- Bio-Tech Research Center, Shandong Academy of Agricultural Sciences; Shandong Provincial Key Laboratory of Crop Genetic Improvement, Ecology and Physiology, Jinan, 250100, PR China.
| | - Chuanzhi Zhao
- Bio-Tech Research Center, Shandong Academy of Agricultural Sciences; Shandong Provincial Key Laboratory of Crop Genetic Improvement, Ecology and Physiology, Jinan, 250100, PR China.
| | - Lei Hou
- Bio-Tech Research Center, Shandong Academy of Agricultural Sciences; Shandong Provincial Key Laboratory of Crop Genetic Improvement, Ecology and Physiology, Jinan, 250100, PR China.
| | - Changsheng Li
- Bio-Tech Research Center, Shandong Academy of Agricultural Sciences; Shandong Provincial Key Laboratory of Crop Genetic Improvement, Ecology and Physiology, Jinan, 250100, PR China.
| | - Aiqin Li
- Bio-Tech Research Center, Shandong Academy of Agricultural Sciences; Shandong Provincial Key Laboratory of Crop Genetic Improvement, Ecology and Physiology, Jinan, 250100, PR China.
| | - Chuanxi Ma
- Agricultural College, Anhui Agricultural University, Hefei, 230036, PR China.
| | - Xingjun Wang
- Bio-Tech Research Center, Shandong Academy of Agricultural Sciences; Shandong Provincial Key Laboratory of Crop Genetic Improvement, Ecology and Physiology, Jinan, 250100, PR China.
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34
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Li Y, Córdoba-Cañero D, Qian W, Zhu X, Tang K, Zhang H, Ariza RR, Roldán-Arjona T, Zhu JK. An AP endonuclease functions in active DNA demethylation and gene imprinting in Arabidopsis [corrected]. PLoS Genet 2015; 11:e1004905. [PMID: 25569774 PMCID: PMC4287435 DOI: 10.1371/journal.pgen.1004905] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 11/18/2014] [Indexed: 11/19/2022] Open
Abstract
Active DNA demethylation in plants occurs through base excision repair, beginning with removal of methylated cytosine by the ROS1/DME subfamily of 5-methylcytosine DNA glycosylases. Active DNA demethylation in animals requires the DNA glycosylase TDG or MBD4, which functions after oxidation or deamination of 5-methylcytosine, respectively. However, little is known about the steps following DNA glycosylase action in the active DNA demethylation pathways in plants and animals. We show here that the Arabidopsis APE1L protein has apurinic/apyrimidinic endonuclease activities and functions downstream of ROS1 and DME. APE1L and ROS1 interact in vitro and co-localize in vivo. Whole genome bisulfite sequencing of ape1l mutant plants revealed widespread alterations in DNA methylation. We show that the ape1l/zdp double mutant displays embryonic lethality. Notably, the ape1l+/-zdp-/- mutant shows a maternal-effect lethality phenotype. APE1L and the DNA phosphatase ZDP are required for FWA and MEA gene imprinting in the endosperm and are important for seed development. Thus, APE1L is a new component of the active DNA demethylation pathway and, together with ZDP, regulates gene imprinting in Arabidopsis.
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Affiliation(s)
- Yan Li
- Shanghai Center for Plant Stress Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences and Peking-Tsinghua Center for Life Science, Peking University, Beijing, China
| | - Dolores Córdoba-Cañero
- Department of Genetics, University of Córdoba/Maimonides Institute for Biomedical Research of Cordoba (IMIBIC)/Reina Sofía University Hospital, Córdoba, Spain
| | - Weiqiang Qian
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences and Peking-Tsinghua Center for Life Science, Peking University, Beijing, China
| | - Xiaohong Zhu
- Department of Horticulture & Landscape Architecture, Purdue University, West Lafayette, Indiana, United States of America
| | - Kai Tang
- Department of Horticulture & Landscape Architecture, Purdue University, West Lafayette, Indiana, United States of America
| | - Huiming Zhang
- Shanghai Center for Plant Stress Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Rafael R. Ariza
- Department of Genetics, University of Córdoba/Maimonides Institute for Biomedical Research of Cordoba (IMIBIC)/Reina Sofía University Hospital, Córdoba, Spain
| | - Teresa Roldán-Arjona
- Department of Genetics, University of Córdoba/Maimonides Institute for Biomedical Research of Cordoba (IMIBIC)/Reina Sofía University Hospital, Córdoba, Spain
- * E-mail: (TRA); (JKZ)
| | - Jian-Kang Zhu
- Shanghai Center for Plant Stress Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
- Department of Horticulture & Landscape Architecture, Purdue University, West Lafayette, Indiana, United States of America
- * E-mail: (TRA); (JKZ)
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35
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Nwafor CC, Gribaudo I, Schneider A, Wehrens R, Grando MS, Costantini L. Transcriptome analysis during berry development provides insights into co-regulated and altered gene expression between a seeded wine grape variety and its seedless somatic variant. BMC Genomics 2014; 15:1030. [PMID: 25431125 PMCID: PMC4301461 DOI: 10.1186/1471-2164-15-1030] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 11/14/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Seedless grapes are greatly appreciated for fresh and dry fruit consumption. Parthenocarpy and stenospermocarpy have been described as the main phenomena responsible for seedlessness in Vitis vinifera. However, the key genes underpinning molecular and cellular processes that play a significant role in seed development are not well characterized. To identify important regulators and mechanisms that may be altered in the seedless phenotype, we performed a comprehensive transcriptional analysis to compare the transcriptomes of a popular seeded wine cultivar (wild-type) and its seedless somatic variant (mutant) at three key developmental stages. RESULTS The transcriptomes revealed by Illumina mRNA-Seq technology had approximately 98% of grapevine annotated transcripts and about 80% of them were commonly expressed in the two lines. Differential gene expression analysis revealed a total of 1075 differentially expressed genes (DE) in the pairwise comparison of developmental stages, which included DE genes specific to the wild-type background, DE genes specific to the mutant background and DE genes commonly shared in both backgrounds. The analysis of differential expression patterns and functional category enrichment of wild-type and mutant DE genes highlighted significant coordination and enrichment of pollen and ovule developmental pathways. The expression of some selected DE genes was further confirmed by real-time RT-PCR analysis. CONCLUSIONS This study represents the most comprehensive attempt to characterize the genetic bases of seed formation in grapevine. With a high throughput method, we have shown that a seeded wine grape and its seedless somatic variant are similar in several biological processes. Nevertheless, we could identify an inventory of genes with altered expression in the mutant compared to the wild-type, which may be responsible for the seedless phenotype. The genes located within known genomic regions regulating seed content may be used for the development of molecular tools to assist table grape breeding. Therefore the data reported here have provided a rich genomic resource for practical use and functional characterization of the genes that potentially underpin seedlessness in grapevine.
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Affiliation(s)
| | | | | | | | | | - Laura Costantini
- Fondazione Edmund Mach, Research and Innovation Centre, Via E, Mach 1-38010 San Michele all'Adige, Trento, Italy.
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36
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Lee J, Jang H, Shin H, Choi WL, Mok YG, Huh JH. AP endonucleases process 5-methylcytosine excision intermediates during active DNA demethylation in Arabidopsis. Nucleic Acids Res 2014; 42:11408-18. [PMID: 25228464 PMCID: PMC4191409 DOI: 10.1093/nar/gku834] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
DNA methylation is a primary epigenetic modification regulating gene expression and chromatin structure in many eukaryotes. Plants have a unique DNA demethylation system in that 5-methylcytosine (5mC) is directly removed by DNA demethylases, such as DME/ROS1 family proteins, but little is known about the downstream events. During 5mC excision, DME produces 3′-phosphor-α, β-unsaturated aldehyde and 3′-phosphate by successive β- and δ-eliminations, respectively. The kinetic studies revealed that these 3′-blocking lesions persist for a significant amount of time and at least two different enzyme activities are required to immediately process them. We demonstrate that Arabidopsis AP endonucleases APE1L, APE2 and ARP have distinct functions to process such harmful lesions to allow nucleotide extension. DME expression is toxic to E. coli due to excessive 5mC excision, but expression of APE1L or ARP significantly reduces DME-induced cytotoxicity. Finally, we propose a model of base excision repair and DNA demethylation pathway unique to plants.
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Affiliation(s)
- Jiyoon Lee
- Department of Plant Science, Research Institute for Agriculture and Life Sciences, and Plant Genomics and Breeding Institute, Seoul National University, Seoul 151-921, Korea
| | - Hosung Jang
- Department of Plant Science, Research Institute for Agriculture and Life Sciences, and Plant Genomics and Breeding Institute, Seoul National University, Seoul 151-921, Korea
| | - Hosub Shin
- Department of Plant Science, Research Institute for Agriculture and Life Sciences, and Plant Genomics and Breeding Institute, Seoul National University, Seoul 151-921, Korea
| | - Woo Lee Choi
- Department of Plant Science, Research Institute for Agriculture and Life Sciences, and Plant Genomics and Breeding Institute, Seoul National University, Seoul 151-921, Korea
| | - Young Geun Mok
- Department of Plant Science, Research Institute for Agriculture and Life Sciences, and Plant Genomics and Breeding Institute, Seoul National University, Seoul 151-921, Korea
| | - Jin Hoe Huh
- Department of Plant Science, Research Institute for Agriculture and Life Sciences, and Plant Genomics and Breeding Institute, Seoul National University, Seoul 151-921, Korea
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37
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Sun X, Ling S, Lu Z, Ouyang YD, Liu S, Yao J. OsNF-YB1, a rice endosperm-specific gene, is essential for cell proliferation in endosperm development. Gene 2014; 551:214-21. [PMID: 25178525 DOI: 10.1016/j.gene.2014.08.059] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2014] [Revised: 08/19/2014] [Accepted: 08/28/2014] [Indexed: 12/23/2022]
Abstract
Cell cycle regulators are crucial for normal endosperm development and seed size determination. However, how the cell cycle related genes regulate endosperm development remains unclear. In this study, we reported a rice Nuclear Factor Y (NF-Y) gene OsNF-YB1, which was also identified as an endosperm-specific gene. Transcriptional profiling and promoter analysis revealed that OsNF-YB1 was highly expressed at the early stages of rice endosperm development (5-7 DAP, days after pollination). Repression of OsNF-YB1 resulted in differential expression of the genes in cell cycle pathway, which caused abnormal seeds with defected embryo and endosperm. Basic cytological analysis demonstrated that the reduced endosperm cell numbers disintegrated with the development of those abnormal seeds in OsNF-YB1 RNAi plants. Taken together, these results suggested that the endosperm-specific gene OsNF-YB1 might be a cell cycle regulator and played a role in maintaining the endosperm cell proliferation.
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Affiliation(s)
- Xiaocong Sun
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Sheng Ling
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Zhanhua Lu
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yi-Dan Ouyang
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Shasha Liu
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Jialing Yao
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China.
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38
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Qian W, Miki D, Lei M, Zhu X, Zhang H, Liu Y, Li Y, Lang Z, Wang J, Tang K, Liu R, Zhu JK. Regulation of active DNA demethylation by an α-crystallin domain protein in Arabidopsis. Mol Cell 2014; 55:361-71. [PMID: 25002145 DOI: 10.1016/j.molcel.2014.06.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Revised: 04/03/2014] [Accepted: 05/20/2014] [Indexed: 12/20/2022]
Abstract
DNA methylation patterns are dynamically controlled by DNA methylation and active DNA demethylation, but the mechanisms of regulation of active DNA demethylation are not well understood. Through forward genetic screens for Arabidopsis mutants showing DNA hypermethylation at specific loci and increased silencing of reporter genes, we identified IDM2 (increased DNA methylation 2) as a regulator of DNA demethylation and gene silencing. IDM2 dysfunction causes DNA hypermethylation and silencing of reporter genes and some endogenous genes. These effects of idm2 mutations are similar to those of mutations in IDM1, a regulator of active DNA demethylation. IDM2 encodes an α-crystallin domain protein in the nucleus. IDM2 and IDM1 interact physically and partially colocalize at discrete subnuclear foci. IDM2 is required for the full activity of H3K18 acetylation but not H3K23 acetylation of IDM1 in planta. Our results suggest that IDM2 functions in active DNA demethylation and in antisilencing by regulating IDM1.
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Affiliation(s)
- Weiqiang Qian
- Shanghai Center for Plant Stress Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China; Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47906, USA
| | - Daisuke Miki
- Shanghai Center for Plant Stress Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Mingguang Lei
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47906, USA
| | - Xiaohong Zhu
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47906, USA
| | - Huiming Zhang
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47906, USA
| | - Yunhua Liu
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47906, USA
| | - Yan Li
- Shanghai Center for Plant Stress Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Zhaobo Lang
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47906, USA
| | - Jing Wang
- Shanghai Center for Plant Stress Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Kai Tang
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47906, USA
| | - Renyi Liu
- Shanghai Center for Plant Stress Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Jian-Kang Zhu
- Shanghai Center for Plant Stress Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China; Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47906, USA.
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39
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Ng DWK, Miller M, Yu HH, Huang TY, Kim ED, Lu J, Xie Q, McClung CR, Chen ZJ. A Role for CHH Methylation in the Parent-of-Origin Effect on Altered Circadian Rhythms and Biomass Heterosis in Arabidopsis Intraspecific Hybrids. THE PLANT CELL 2014; 26:2430-2440. [PMID: 24894042 PMCID: PMC4114943 DOI: 10.1105/tpc.113.115980] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Hybrid plants and animals often show increased levels of growth and fitness, a phenomenon known as hybrid vigor or heterosis. Circadian rhythms optimize physiology and metabolism in plants and animals. In plant hybrids and polyploids, expression changes of the genes within the circadian regulatory network, such as CIRCADIAN CLOCK ASSOCIATED1 (CCA1), lead to heterosis. However, the relationship between allelic CCA1 expression and heterosis has remained elusive. Here, we show a parent-of-origin effect on altered circadian rhythms and heterosis in Arabidopsis thaliana F1 hybrids. This parent-of-origin effect on biomass heterosis correlates with altered CCA1 expression amplitudes, which are associated with methylation levels of CHH (where H = A, T, or C) sites in the promoter region. The direction of rhythmic expression and hybrid vigor is reversed in reciprocal F1 crosses involving mutants that are defective in the RNA-directed DNA methylation pathway (argonaute4 and nuclear RNA polymerase D1a) but not in the maintenance methylation pathway (methyltransferase1 and decrease in DNA methylation1). This parent-of-origin effect on circadian regulation and heterosis is established during early embryogenesis and maintained throughout growth and development.
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Affiliation(s)
- Danny W-K Ng
- Department of Molecular Biosciences, Center for Computational Biology and Bioinformatics and Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas 78712-0159 Department of Biology, Hong Kong Baptist University, Kowloon, Hong Kong
| | - Marisa Miller
- Department of Molecular Biosciences, Center for Computational Biology and Bioinformatics and Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas 78712-0159
| | - Helen H Yu
- Department of Molecular Biosciences, Center for Computational Biology and Bioinformatics and Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas 78712-0159
| | - Tien-Yu Huang
- Department of Molecular Biosciences, Center for Computational Biology and Bioinformatics and Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas 78712-0159
| | - Eun-Deok Kim
- Department of Molecular Biosciences, Center for Computational Biology and Bioinformatics and Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas 78712-0159
| | - Jie Lu
- Department of Molecular Biosciences, Center for Computational Biology and Bioinformatics and Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas 78712-0159
| | - Qiguang Xie
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755-3563
| | - C Robertson McClung
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755-3563
| | - Z Jeffrey Chen
- Department of Molecular Biosciences, Center for Computational Biology and Bioinformatics and Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas 78712-0159 State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
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40
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Kim MY, Zilberman D. DNA methylation as a system of plant genomic immunity. TRENDS IN PLANT SCIENCE 2014; 19:320-6. [PMID: 24618094 DOI: 10.1016/j.tplants.2014.01.014] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2013] [Revised: 01/28/2014] [Accepted: 01/31/2014] [Indexed: 05/06/2023]
Abstract
Transposons are selfish genetic sequences that can increase their copy number and inflict substantial damage on their hosts. To combat these genomic parasites, plants have evolved multiple pathways to identify and silence transposons by methylating their DNA. Plants have also evolved mechanisms to limit the collateral damage from the antitransposon machinery. In this review, we examine recent developments that have elucidated many of the molecular workings of these pathways. We also highlight the evidence that the methylation and demethylation pathways interact, indicating that plants have a highly sophisticated, integrated system of transposon defense that has an important role in the regulation of gene expression.
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Affiliation(s)
- M Yvonne Kim
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA
| | - Daniel Zilberman
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA.
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41
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Brooks SC, Fischer RL, Huh JH, Eichman BF. 5-methylcytosine recognition by Arabidopsis thaliana DNA glycosylases DEMETER and DML3. Biochemistry 2014; 53:2525-32. [PMID: 24678721 PMCID: PMC4004242 DOI: 10.1021/bi5002294] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
Methylation of cytosine to 5-methylcytosine
(5mC) is important
for gene expression, gene imprinting, X-chromosome inactivation, and
transposon silencing. Active demethylation in animals is believed
to proceed by DNA glycosylase removal of deaminated or oxidized 5mC.
In plants, 5mC is removed from the genome directly by the DEMETER
(DME) family of DNA glycosylases. Arabidopsis thaliana DME excises 5mC to activate expression of maternally imprinted genes.
Although the related Repressor of Silencing 1 (ROS1) enzyme has been
characterized, the molecular basis for 5mC recognition by DME has
not been investigated. Here, we present a structure–function
analysis of DME and the related DME-like 3 (DML3) glycosylases for
5mC and its oxidized derivatives. Relative to 5mC, DME and DML3 exhibited
robust activity toward 5-hydroxymethylcytosine, limited activity for
5-carboxylcytosine, and no activity for 5-formylcytosine. We used
homology modeling and mutational analysis of base excision and DNA
binding to identify residues important for recognition of 5mC within
the context of DNA and inside the enzyme active site. Our results
indicate that the 5mC binding pocket is composed of residues from
discrete domains and is responsible for discrimination against 5mC
derivatives, and suggest that DME, ROS1, and DML3 utilize subtly different
mechanisms to probe the DNA duplex for cytosine modifications.
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Affiliation(s)
- Sonja C Brooks
- Department of Biological Sciences and Center for Structural Biology, Vanderbilt University , Nashville, Tennessee 37232, United States
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42
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Jang H, Shin H, Eichman BF, Huh JH. Excision of 5-hydroxymethylcytosine by DEMETER family DNA glycosylases. Biochem Biophys Res Commun 2014; 446:1067-72. [PMID: 24661881 DOI: 10.1016/j.bbrc.2014.03.060] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2014] [Accepted: 03/15/2014] [Indexed: 12/25/2022]
Abstract
In plants and animals, 5-methylcytosine (5mC) serves as an epigenetic mark to repress gene expression, playing critical roles for cellular differentiation and transposon silencing. Mammals also have 5-hydroxymethylcytosine (5hmC), resulting from hydroxylation of 5mC by TET family-enzymes. 5hmC is abundant in mouse Purkinje neurons and embryonic stem cells, and regarded as an important intermediate for active DNA demethylation in mammals. However, the presence of 5hmC in plants has not been clearly demonstrated. In Arabidopsis, the DEMETER (DME) family DNA glycosylases efficiently remove 5mC, which results in DNA demethylation and transcriptional activation of target genes. Here we show that DME and ROS1 have a significant 5hmC excision activity in vitro, although we detected no 5hmC in Arabidopsis, suggesting that it is very unlikely for plants to utilize 5hmC as a DNA demethylation intermediate. Our results indicate that both plants and animals have 5mC in common but DNA demethylation systems have independently evolved with distinct mechanisms.
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Affiliation(s)
- Hosung Jang
- Department of Plant Science, Research Institute for Agriculture and Life Sciences, and Plant Genomics and Breeding Institute, Seoul National University, Seoul 151-921, Republic of Korea
| | - Hosub Shin
- Department of Plant Science, Research Institute for Agriculture and Life Sciences, and Plant Genomics and Breeding Institute, Seoul National University, Seoul 151-921, Republic of Korea
| | - Brandt F Eichman
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, USA
| | - Jin Hoe Huh
- Department of Plant Science, Research Institute for Agriculture and Life Sciences, and Plant Genomics and Breeding Institute, Seoul National University, Seoul 151-921, Republic of Korea.
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43
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Waters AJ, Bilinski P, Eichten SR, Vaughn MW, Ross-Ibarra J, Gehring M, Springer NM. Comprehensive analysis of imprinted genes in maize reveals allelic variation for imprinting and limited conservation with other species. Proc Natl Acad Sci U S A 2013; 110:19639-44. [PMID: 24218619 PMCID: PMC3845156 DOI: 10.1073/pnas.1309182110] [Citation(s) in RCA: 102] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
In plants, a subset of genes exhibit imprinting in endosperm tissue such that expression is primarily from the maternal or paternal allele. Imprinting may arise as a consequence of mechanisms for silencing of transposons during reproduction, and in some cases imprinted expression of particular genes may provide a selective advantage such that it is conserved across species. Separate mechanisms for the origin of imprinted expression patterns and maintenance of these patterns may result in substantial variation in the targets of imprinting in different species. Here we present deep sequencing of RNAs isolated from reciprocal crosses of four diverse maize genotypes, providing a comprehensive analysis that allows evaluation of imprinting at more than 95% of endosperm-expressed genes. We find that over 500 genes exhibit statistically significant parent-of-origin effects in maize endosperm tissue, but focused our analyses on a subset of these genes that had >90% expression from the maternal allele (69 genes) or from the paternal allele (108 genes) in at least one reciprocal cross. Over 10% of imprinted genes show evidence of allelic variation for imprinting. A comparison of imprinting in maize and rice reveals that 13% of genes with syntenic orthologs in both species exhibit conserved imprinting. Genes that exhibit conserved imprinting between maize and rice have elevated nonsynonymous to synonymous substitution ratios compared with other imprinted genes, suggesting a history of more rapid evolution. Together, these data suggest that imprinting only has functional relevance at a subset of loci that currently exhibit imprinting in maize.
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Affiliation(s)
- Amanda J. Waters
- Microbial and Plant Genomics Institute and Department of Plant Biology, University of Minnesota, St. Paul, MN 55108
| | | | - Steven R. Eichten
- Microbial and Plant Genomics Institute and Department of Plant Biology, University of Minnesota, St. Paul, MN 55108
| | - Matthew W. Vaughn
- Texas Advanced Computing Center, University of Texas–Austin, Austin TX 78758
| | - Jeffrey Ross-Ibarra
- Department of Plant Sciences and
- The Genome Center and Center for Population Biology, University of California, Davis, CA 95616
| | - Mary Gehring
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142; and
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Nathan M. Springer
- Microbial and Plant Genomics Institute and Department of Plant Biology, University of Minnesota, St. Paul, MN 55108
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44
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Getting rid of DNA methylation. Trends Cell Biol 2013; 24:136-43. [PMID: 24119665 DOI: 10.1016/j.tcb.2013.09.001] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 09/03/2013] [Accepted: 09/04/2013] [Indexed: 11/22/2022]
Abstract
Methylation of cytosine within DNA is associated with transcriptional repression and genome surveillance. In plants and animals, conserved pathways exist to establish and maintain this epigenetic mark. Mechanisms underlining its removal are, however, diverse and controversial and can depend on DNA synthesis (passive) or be independent of it (active). Ten-eleven translocation (Tet)-mediated conversion of 5-methylcytosine (5mC) into 5-hydroxymethylcytosine (5hmC) has recently been evoked as a possible mechanism in the initiation of active and passive DNA demethylation. This review discuses the recent progress in this exciting area.
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45
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Ha M. Understanding the chromatin remodeling code. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2013; 211:137-145. [PMID: 23987819 DOI: 10.1016/j.plantsci.2013.07.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 07/15/2013] [Accepted: 07/17/2013] [Indexed: 06/02/2023]
Abstract
Remodeling a chromatin structure enables the genetic elements stored in a genome to function in a condition-specific manner and predisposes the interactions between cis-regulatory elements and trans-acting factors. A chromatin signature can be an indicator of the activity of the underlying genetic elements. This paper reviews recent studies showing that the combination and arrangements of chromatin remodeling marks play roles as chromatin code affecting the activity of genetic elements. This paper also reviews recent studies inferring the primary DNA sequence contexts associated with chromatin remodeling that suggest interactions between genetic and epigenetic factors. We conclude that chromatin remodeling, which provides accurate models of gene expression and morphological variations, may help to find the biological marks that cannot be detected by genome-wide association study or genetic study.
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Affiliation(s)
- Misook Ha
- Samsung Advanced Institute of Technology, Samsung Electronics Corporation, Yongin-Si, Gyeonggi-Do, South Korea.
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46
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Zhou SR, Yin LL, Xue HW. Functional genomics based understanding of rice endosperm development. CURRENT OPINION IN PLANT BIOLOGY 2013; 16:236-46. [PMID: 23582455 DOI: 10.1016/j.pbi.2013.03.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2012] [Revised: 03/13/2013] [Accepted: 03/13/2013] [Indexed: 05/05/2023]
Abstract
Seed development, especially the relevant regulatory mechanism and genetic network are of fundamental scientific interest. Seed development consists of the development of embryo and endosperm; and endosperm development of rice (model species of monocots) is closely related to grain yield and quality. Recent genetic studies, together with other approaches, including transcriptome and proteomics analysis, high-throughput sequencing (RNA-seq, ChIP-seq), revealed the crucial roles of genetic and epigenetic controls in rice endosperm development. Here we summarize and update the genetic networks involved in the regulation of endosperm initiation, cell cycle regulation, aleurone layer specification, starch synthesis, storage protein accumulation and endosperm size, and the interactions between embryo and endosperm.
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Affiliation(s)
- Shi-Rong Zhou
- National Key Laboratory of Plant Molecular Genetics, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300, Fenglin Road, 200032 Shanghai, China
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47
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Flores KB, Wolschin F, Amdam GV. The role of methylation of DNA in environmental adaptation. Integr Comp Biol 2013; 53:359-72. [PMID: 23620251 DOI: 10.1093/icb/ict019] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Methylation of DNA is an epigenetic mechanism that influences patterns of gene expression. DNA methylation marks contribute to adaptive phenotypic variation but are erased during development. The role of DNA methylation in adaptive evolution is therefore unclear. We propose that environmentally-induced DNA methylation causes phenotypic heterogeneity that provides a substrate for selection via forces that act on the epigenetic machinery. For example, selection can alter environmentally-induced methylation of DNA by acting on the molecular mechanisms used for the genomic targeting of DNA methylation. Another possibility is that specific methylation marks that are environmentally-induced, yet non-heritable, could influence preferential survival and lead to consistent methylation of the same genomic regions over time. As methylation of DNA is known to increase the likelihood of cytosine-to-thymine transitions, non-heritable adaptive methylation marks can drive an increased likelihood of mutations targeted to regions that are consistently marked across several generations. Some of these mutations could capture, genetically, the phenotypic advantage of the epigenetic mark. Thereby, selectively favored transitory alterations in the genome invoked by DNA methylation could ultimately become selectable genetic variation through mutation. We provide evidence for these concepts using examples from different taxa, but focus on experimental data on large-scale DNA sequencing that expose between-group genetic variation after bidirectional selection on honeybees, Apis mellifera.
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Affiliation(s)
- Kevin B Flores
- School of Life Sciences, Arizona State University, PO Box 874501, Tempe, AZ 85287, USA.
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48
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Nallamilli BRR, Zhang J, Mujahid H, Malone BM, Bridges SM, Peng Z. Polycomb group gene OsFIE2 regulates rice (Oryza sativa) seed development and grain filling via a mechanism distinct from Arabidopsis. PLoS Genet 2013; 9:e1003322. [PMID: 23505380 PMCID: PMC3591265 DOI: 10.1371/journal.pgen.1003322] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2012] [Accepted: 12/29/2012] [Indexed: 11/19/2022] Open
Abstract
Cereal endosperm represents 60% of the calories consumed by human beings worldwide. In addition, cereals also serve as the primary feedstock for livestock. However, the regulatory mechanism of cereal endosperm and seed development is largely unknown. Polycomb complex has been shown to play a key role in the regulation of endosperm development in Arabidopsis, but its role in cereal endosperm development remains obscure. Additionally, the enzyme activities of the polycomb complexes have not been demonstrated in plants. Here we purified the rice OsFIE2-polycomb complex using tandem affinity purification and demonstrated its specific H3 methyltransferase activity. We found that the OsFIE2 gene product was responsible for H3K27me3 production specifically in vivo. Genetic studies showed that a reduction of OsFIE2 expression led to smaller seeds, partially filled seeds, and partial loss of seed dormancy. Gene expression and proteomics analyses found that the starch synthesis rate limiting step enzyme and multiple storage proteins are down-regulated in OsFIE2 reduction lines. Genome wide ChIP–Seq data analysis shows that H3K27me3 is associated with many genes in the young seeds. The H3K27me3 modification and gene expression in a key helix-loop-helix transcription factor is shown to be regulated by OsFIE2. Our results suggest that OsFIE2-polycomb complex positively regulates rice endosperm development and grain filling via a mechanism highly different from that in Arabidopsis. Rice is the staple food for over half of the world's population and an important feedstock for livestock. The rice grain is mainly endosperm tissue. The regulatory mechanism of rice endosperm development is still largely unknown thus far. Understanding the underlying mechanism will lead to crop yield and quality improvement in the long term, besides gaining new knowledge. Polycomb complex is a protein complex with a potential role in endosperm development according to prior publications. In this manuscript, we purified the rice OsFIE2-polycomb protein complex and demonstrated the enzyme activity of the complex. Genetic studies showed that a reduction of polycomb group gene OsFIE2 expression led to smaller seeds, partially filled seeds, and seed germination before seed maturation. Gene expression and proteomics analyses found that the starch synthesis rate limiting step enzyme and multiple storage proteins are down-regulated while a key transcription factor is up-regulated in OsFIE2 reduction lines. In addition, we identified many loci in the rice genome whose histone proteins are modified by the polycomb complex enzyme via a method called ChIP–Seq. Our results demonstrate that OsFIE2-polycomb complex positively regulates rice grain development via a mechanism distinct from that in Arabidopsis and provide new insight into the regulation of rice grain development.
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Affiliation(s)
- Babi Ramesh Reddy Nallamilli
- Department of Biochemistry and Molecular Biology, Mississippi State University, Mississippi State, Mississippi, United States of America
| | - Jian Zhang
- Department of Biochemistry and Molecular Biology, Mississippi State University, Mississippi State, Mississippi, United States of America
| | - Hana Mujahid
- Department of Biochemistry and Molecular Biology, Mississippi State University, Mississippi State, Mississippi, United States of America
| | - Brandon M. Malone
- Department of Computer Science and Engineering, Mississippi State University, Mississippi State, Mississippi, United States of America
- Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Mississippi State, Mississippi, United States of America
| | - Susan M. Bridges
- Department of Computer Science and Engineering, Mississippi State University, Mississippi State, Mississippi, United States of America
- Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Mississippi State, Mississippi, United States of America
| | - Zhaohua Peng
- Department of Biochemistry and Molecular Biology, Mississippi State University, Mississippi State, Mississippi, United States of America
- * E-mail:
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Tonosaki K, Michiba K, Bang SW, Kitashiba H, Kaneko Y, Nishio T. Genetic analysis of hybrid seed formation ability of Brassica rapa in intergeneric crossings with Raphanus sativus. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2013. [PMID: 23203221 DOI: 10.1007/s00122-012-2021-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
A hybridization barrier leads to the inability of seed formation after intergeneric crossings between Brassica rapa and Raphanus sativus. Most B. rapa lines cannot set intergeneric hybrid seeds because of embryo breakdown, but a B. rapa line obtained from turnip cultivar 'Shogoin-kabu' is able to produce a large number of hybrid seeds as a maternal parent by crossings with R. sativus. In 'Shogoin-kabu' crossed with R. sativus, developments of embryos and endosperms were slower than those in intraspecific crossings, but some of them grew to mature seeds without embryo breakdown. Intergeneric hybrid seeds were obtained in a 'Shogoin-kabu' line at a rate of 0.13 per pollinated flower, while no hybrid seeds were obtained in a line developed from Chinese cabbage cultivar 'Chiifu'. F(1) hybrid plants between the lines of 'Shogoin-kabu' and 'Chiifu' set a larger number of hybrid seeds per flower, 0.68, than both the parental lines. Quantitative trait loci (QTLs) for hybrid seed formation were analyzed after intergeneric crossings using two different F(2) populations derived from the F(1) hybrids, and three QTLs with significant logarithm of odds scores were detected. Among them, two QTLs, i.e., one in linkage group A10 and the other in linkage group A01, were detected in both the F(2) populations. These two QTLs had contrary effects on the number of hybrid seeds. Epistatic interaction between these two QTLs was revealed. Possible candidate genes controlling hybrid seed formation ability in QTL regions were inferred using the published B. rapa genome sequences.
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Affiliation(s)
- K Tonosaki
- Graduate School of Agricultural Science, Tohoku University, 1-1 Tsutsumidori-Amamiyamachi, Aoba-ku, Sendai, Miyagi 981-8555, Japan
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Kesavan M, Song JT, Seo HS. Seed size: a priority trait in cereal crops. PHYSIOLOGIA PLANTARUM 2013; 147:113-20. [PMID: 22680622 DOI: 10.1111/j.1399-3054.2012.01664.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Revised: 05/12/2012] [Accepted: 05/15/2012] [Indexed: 05/21/2023]
Abstract
Crop production and productivity must be increased to provide a balanced diet for the global population. The entire genome sequences of crop species allow the elucidation of genes that regulate important traits related to the final crop seed yield, which frequently depends mainly on seed size. Seed size is a major factor that controls seed quantity and it is strongly affected by various biotic, abiotic and genetic factors. Epigenetic marks in the genome and phytohormones are also important factors affecting seed growth and development. Several genes are known to be involved in the control of seed size, but their interaction and functional characterization have yet to be resolved. In this review, we discuss the different factors that govern seed size in cereal crops and Arabidopsis.
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Affiliation(s)
- Markkandan Kesavan
- Department of Plant Science, Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Korea
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